Release v1.6.0 (#324)

* Update version and changelog for v1.6.0
* Update docs
diff --git a/docs/dyn/compute_v1.instanceGroupManagers.html b/docs/dyn/compute_v1.instanceGroupManagers.html
index 3068e0b..3b92f3c 100644
--- a/docs/dyn/compute_v1.instanceGroupManagers.html
+++ b/docs/dyn/compute_v1.instanceGroupManagers.html
@@ -99,7 +99,7 @@
   <code><a href="#list">list(project, zone, orderBy=None, maxResults=None, pageToken=None, filter=None)</a></code></p>
 <p class="firstline">Retrieves a list of managed instance groups that are contained within the specified project and zone.</p>
 <p class="toc_element">
-  <code><a href="#listManagedInstances">listManagedInstances(project, zone, instanceGroupManager)</a></code></p>
+  <code><a href="#listManagedInstances">listManagedInstances(project, zone, instanceGroupManager, order_by=None, maxResults=None, pageToken=None, filter=None)</a></code></p>
 <p class="firstline">Lists all of the instances in the managed instance group. Each instance in the list has a currentAction, which indicates the action that the managed instance group is performing on the instance. For example, if the group is still creating an instance, the currentAction is CREATING. If a previous action failed, the list displays the errors for that failed action.</p>
 <p class="toc_element">
   <code><a href="#list_next">list_next(previous_request, previous_response)</a></code></p>
@@ -181,7 +181,7 @@
     },
     "endTime": "A String", # [Output Only] The time that this operation was completed. This value is in RFC3339 text format.
     "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
-    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. If creating a persistent disk snapshot, this points to the persistent disk that the snapshot was created from.
+    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. For operations related to creating a snapshot, this points to the persistent disk that the snapshot was created from.
   }</pre>
 </div>
 
@@ -341,7 +341,7 @@
     },
     "endTime": "A String", # [Output Only] The time that this operation was completed. This value is in RFC3339 text format.
     "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
-    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. If creating a persistent disk snapshot, this points to the persistent disk that the snapshot was created from.
+    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. For operations related to creating a snapshot, this points to the persistent disk that the snapshot was created from.
   }</pre>
 </div>
 
@@ -409,7 +409,7 @@
     },
     "endTime": "A String", # [Output Only] The time that this operation was completed. This value is in RFC3339 text format.
     "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
-    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. If creating a persistent disk snapshot, this points to the persistent disk that the snapshot was created from.
+    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. For operations related to creating a snapshot, this points to the persistent disk that the snapshot was created from.
   }</pre>
 </div>
 
@@ -557,7 +557,7 @@
     },
     "endTime": "A String", # [Output Only] The time that this operation was completed. This value is in RFC3339 text format.
     "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
-    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. If creating a persistent disk snapshot, this points to the persistent disk that the snapshot was created from.
+    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. For operations related to creating a snapshot, this points to the persistent disk that the snapshot was created from.
   }</pre>
 </div>
 
@@ -635,13 +635,17 @@
 </div>
 
 <div class="method">
-    <code class="details" id="listManagedInstances">listManagedInstances(project, zone, instanceGroupManager)</code>
+    <code class="details" id="listManagedInstances">listManagedInstances(project, zone, instanceGroupManager, order_by=None, maxResults=None, pageToken=None, filter=None)</code>
   <pre>Lists all of the instances in the managed instance group. Each instance in the list has a currentAction, which indicates the action that the managed instance group is performing on the instance. For example, if the group is still creating an instance, the currentAction is CREATING. If a previous action failed, the list displays the errors for that failed action.
 
 Args:
   project: string, Project ID for this request. (required)
   zone: string, The name of the zone where the managed instance group is located. (required)
   instanceGroupManager: string, The name of the managed instance group. (required)
+  order_by: string, A parameter
+  maxResults: integer, A parameter
+  pageToken: string, A parameter
+  filter: string, A parameter
 
 Returns:
   An object of the form:
@@ -755,7 +759,7 @@
     },
     "endTime": "A String", # [Output Only] The time that this operation was completed. This value is in RFC3339 text format.
     "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
-    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. If creating a persistent disk snapshot, this points to the persistent disk that the snapshot was created from.
+    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. For operations related to creating a snapshot, this points to the persistent disk that the snapshot was created from.
   }</pre>
 </div>
 
@@ -815,7 +819,7 @@
     },
     "endTime": "A String", # [Output Only] The time that this operation was completed. This value is in RFC3339 text format.
     "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
-    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. If creating a persistent disk snapshot, this points to the persistent disk that the snapshot was created from.
+    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. For operations related to creating a snapshot, this points to the persistent disk that the snapshot was created from.
   }</pre>
 </div>
 
@@ -881,7 +885,7 @@
     },
     "endTime": "A String", # [Output Only] The time that this operation was completed. This value is in RFC3339 text format.
     "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
-    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. If creating a persistent disk snapshot, this points to the persistent disk that the snapshot was created from.
+    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. For operations related to creating a snapshot, this points to the persistent disk that the snapshot was created from.
   }</pre>
 </div>
 
@@ -950,7 +954,7 @@
     },
     "endTime": "A String", # [Output Only] The time that this operation was completed. This value is in RFC3339 text format.
     "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
-    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. If creating a persistent disk snapshot, this points to the persistent disk that the snapshot was created from.
+    "targetLink": "A String", # [Output Only] The URL of the resource that the operation modifies. For operations related to creating a snapshot, this points to the persistent disk that the snapshot was created from.
   }</pre>
 </div>