Release v1.6.0 (#324)

* Update version and changelog for v1.6.0
* Update docs
diff --git a/docs/dyn/drive_v2.realtime.html b/docs/dyn/drive_v2.realtime.html
index 63cdfa1..c3e29d2 100644
--- a/docs/dyn/drive_v2.realtime.html
+++ b/docs/dyn/drive_v2.realtime.html
@@ -81,7 +81,7 @@
   <code><a href="#get_media">get_media(fileId, revision=None)</a></code></p>
 <p class="firstline">Exports the contents of the Realtime API data model associated with this file as JSON.</p>
 <p class="toc_element">
-  <code><a href="#update">update(fileId, media_body=None, baseRevision=None)</a></code></p>
+  <code><a href="#update">update(fileId, media_body=None, media_mime_type=None, baseRevision=None)</a></code></p>
 <p class="firstline">Overwrites the Realtime API data model associated with this file with the provided JSON data model.</p>
 <h3>Method Details</h3>
 <div class="method">
@@ -105,12 +105,13 @@
 </div>
 
 <div class="method">
-    <code class="details" id="update">update(fileId, media_body=None, baseRevision=None)</code>
+    <code class="details" id="update">update(fileId, media_body=None, media_mime_type=None, baseRevision=None)</code>
   <pre>Overwrites the Realtime API data model associated with this file with the provided JSON data model.
 
 Args:
   fileId: string, The ID of the file that the Realtime API data model is associated with. (required)
   media_body: string, The filename of the media request body, or an instance of a MediaUpload object.
+  media_mime_type: string, The MIME type of the media request body, or an instance of a MediaUpload object.
   baseRevision: string, The revision of the model to diff the uploaded model against. If set, the uploaded model is diffed against the provided revision and those differences are merged with any changes made to the model after the provided revision. If not set, the uploaded model replaces the current model on the server.
 </pre>
 </div>