read the docs fix

docs/conf.py

@@ -257,8 +257,10 @@ texinfo_documents = [
 # If true, do not generate a @detailmenu in the "Top" node's menu.
 #texinfo_no_detailmenu = False
 
-import sphinx_rtd_theme
-
-html_theme = "sphinx_rtd_theme"
+# on_rtd is whether we are on readthedocs.org, this line of code grabbed from docs.readthedocs.org
+on_rtd = os.environ.get('READTHEDOCS', None) == 'True'
 
+if not on_rtd:  # only import and set the theme if we're building docs locally
+    import sphinx_rtd_theme
+    html_theme = 'sphinx_rtd_theme'
     html_theme_path = [sphinx_rtd_theme.get_html_theme_path()]