use rtd theme

docs/conf.py

@@ -116,7 +116,18 @@
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
-html_theme = 'alabaster'
+html_theme = 'default'
+
+import os
+on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
+
+if not on_rtd:  # only import and set the theme if we're building docs locally
+    try:
+        import sphinx_rtd_theme
+        html_theme = "sphinx_rtd_theme"
+        html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]
+    except:
+        pass
 
 # Theme options are theme-specific and customize the look and feel of a theme
 # further.  For a list of options available for each theme, see the