fix: drop python 3.6

.gitignore

@@ -34,3 +34,7 @@ tests/data/user-key.json
 # Generated files
 pylintrc
 pylintrc.test
+
+# Test logs
+coverage.xml
+*sponge_log.xml

docs/CHANGELOG.md

@@ -0,0 +1 @@
+../CHANGELOG.md

docs/README.rst

@@ -0,0 +1 @@
+../README.rst

docs/_static/custom.css

@@ -0,0 +1,20 @@
+div#python2-eol {
+	border-color: red;
+	border-width: medium;
+}
+
+/* Ensure minimum width for 'Parameters' / 'Returns' column */
+dl.field-list > dt {
+    min-width: 100px
+}
+
+/* Insert space between methods for readability */
+dl.method {
+	padding-top: 10px;
+	padding-bottom: 10px
+}
+
+/* Insert empty space between classes */
+dl.class {
+	padding-bottom: 50px
+}

docs/_templates/layout.html

@@ -0,0 +1,50 @@
+
+{% extends "!layout.html" %}
+{%- block content %}
+{%- if theme_fixed_sidebar|lower == 'true' %}
+  <div class="document">
+    {{ sidebar() }}
+    {%- block document %}
+      <div class="documentwrapper">
+      {%- if render_sidebar %}
+        <div class="bodywrapper">
+      {%- endif %}
+
+          {%- block relbar_top %}
+            {%- if theme_show_relbar_top|tobool %}
+              <div class="related top">
+                &nbsp;
+                {{- rellink_markup () }}
+              </div>
+            {%- endif %}
+          {% endblock %}
+
+          <div class="body" role="main">
+          	<div class="admonition" id="python2-eol"> 
+          	 As of January 1, 2020 this library no longer supports Python 2 on the latest released version. 
+          	 Library versions released prior to that date will continue to be available. For more information please
+          	 visit <a href="https://cloud.google.com/python/docs/python2-sunset/">Python 2 support on Google Cloud</a>.
+          	</div>
+            {% block body %} {% endblock %}
+          </div>
+
+          {%- block relbar_bottom %}
+            {%- if theme_show_relbar_bottom|tobool %}
+              <div class="related bottom">
+                &nbsp;
+                {{- rellink_markup () }}
+              </div>
+            {%- endif %}
+          {% endblock %}
+
+      {%- if render_sidebar %}
+        </div>
+      {%- endif %}
+      </div>
+    {%- endblock %}
+    <div class="clearer"></div>
+  </div>
+{%- else %}
+{{ super() }}
+{%- endif %}
+{%- endblock %}