always use sphinx_rtd_theme

Author: Chilipp

docs/conf.py

@@ -130,11 +130,7 @@
 
 # The theme to use for HTML and HTML Help pages.  See the documentation for
 # a list of builtin themes.
-
-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()]
+html_theme = 'sphinx_rtd_theme'
 
 # otherwise, readthedocs.org uses their theme by default, so no need to specify