Release v1.6.0 (#324)

* Update version and changelog for v1.6.0
* Update docs
diff --git a/docs/dyn/compute_alpha.licenses.html b/docs/dyn/compute_alpha.licenses.html
index 6bce5b6..3195be3 100644
--- a/docs/dyn/compute_alpha.licenses.html
+++ b/docs/dyn/compute_alpha.licenses.html
@@ -90,9 +90,11 @@
   An object of the form:
 
     { # A license resource.
-    "chargesUseFee": True or False, # [Output Only] If true, the customer will be charged license fee for running software that contains this license on an instance.
     "kind": "compute#license", # [Output Only] Type of resource. Always compute#license for licenses.
     "name": "A String", # [Output Only] Name of the resource. The name is 1-63 characters long and complies with RFC1035.
+    "chargesUseFee": True or False, # [Output Only] If true, the customer will be charged license fee for running software that contains this license on an instance.
+    "licenseCode": "A String", # [Output Only] The unique code used to attach this license to images, snapshots, and disks.
+    "transferable": True or False, # If false, licenses will not be copied from the source resource when creating an image from a disk, disk from snapshot, or snapshot from disk.
     "selfLink": "A String", # [Output Only] Server-defined URL for the resource.
   }</pre>
 </div>