Release v1.6.0 (#324)

* Update version and changelog for v1.6.0
* Update docs
diff --git a/docs/dyn/compute_beta.urlMaps.html b/docs/dyn/compute_beta.urlMaps.html
index bfa777b..4ca0cb4 100644
--- a/docs/dyn/compute_beta.urlMaps.html
+++ b/docs/dyn/compute_beta.urlMaps.html
@@ -159,7 +159,7 @@
     },
     "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>
 
@@ -323,7 +323,7 @@
     },
     "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>
 
@@ -339,6 +339,7 @@
 
 {
     "path": "A String",
+    "host": "A String", # If set, this invalidation rule will only apply to requests with a Host header matching host.
   }
 
 
@@ -388,7 +389,7 @@
     },
     "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>
 
@@ -590,7 +591,7 @@
     },
     "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>
 
@@ -724,7 +725,7 @@
     },
     "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>