Release v1.6.0 (#324)

* Update version and changelog for v1.6.0
* Update docs
diff --git a/docs/dyn/compute_v1.instanceGroups.html b/docs/dyn/compute_v1.instanceGroups.html
index 85fc2a3..9c294f6 100644
--- a/docs/dyn/compute_v1.instanceGroups.html
+++ b/docs/dyn/compute_v1.instanceGroups.html
@@ -177,7 +177,7 @@
     },
     "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>
 
@@ -325,7 +325,7 @@
     },
     "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>
 
@@ -449,7 +449,7 @@
     },
     "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>
 
@@ -663,7 +663,7 @@
     },
     "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>
 
@@ -735,7 +735,7 @@
     },
     "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>