Release v1.6.0 (#324)

* Update version and changelog for v1.6.0
* Update docs
diff --git a/docs/dyn/drive_v3.changes.html b/docs/dyn/drive_v3.changes.html
index 68dc542..0dcb58f 100644
--- a/docs/dyn/drive_v3.changes.html
+++ b/docs/dyn/drive_v3.changes.html
@@ -125,11 +125,13 @@
         "removed": True or False, # Whether the file has been removed from the view of the changes list, for example by deletion or lost access.
         "time": "A String", # The time of this change (RFC 3339 date-time).
         "file": { # The metadata for a file. # The updated state of the file. Present if the file has not been removed.
+          "hasThumbnail": True or False, # Whether this file has a thumbnail.
           "mimeType": "A String", # The MIME type of the file.
               # Drive will attempt to automatically detect an appropriate value from uploaded content if no value is provided. The value cannot be changed unless a new revision is uploaded.
               # If a file is created with a Google Doc MIME type, the uploaded content will be imported if possible. The supported import formats are published in the About resource.
           "modifiedByMeTime": "A String", # The last time the file was modified by the user (RFC 3339 date-time).
-          "thumbnailLink": "A String", # A short-lived link to the file's thumbnail, if available. Typically lasts on the order of hours.
+          "thumbnailLink": "A String", # A short-lived link to the file's thumbnail, if available. Typically lasts on the order of hours. Only populated when the requesting app can access the file's content.
+          "thumbnailVersion": "A String", # The thumbnail version for use in client-contructable thumbnail URLs or thumbnail cache invalidation.
           "explicitlyTrashed": True or False, # Whether the file has been explicitly trashed, as opposed to recursively trashed from a parent folder.
           "isAppAuthorized": True or False, # Whether the file was created or opened by the requesting app.
           "writersCanShare": True or False, # Whether users with only writer permission can modify the file's permissions.
@@ -209,6 +211,7 @@
           "modifiedTime": "A String", # The last time the file was modified by anyone (RFC 3339 date-time).
               # Note that setting modifiedTime will also update modifiedByMeTime for the user.
           "viewedByMe": True or False, # Whether the file has been viewed by this user.
+          "modifiedByMe": True or False, # Whether the file has been modified by this user.
           "owners": [ # The owners of the file. Currently, only certain legacy files may have more than one owner.
             { # Information about a Drive user.
               "me": True or False, # Whether this user is the requesting user.