DOC: Try to add 404 page

.travis.yml

@@ -2,7 +2,7 @@ language: python
 python: "2.7"
 
 install:
-- pip install sphinx sphinx_rtd_theme mock
+- pip install sphinx sphinx_rtd_theme sphinx-notfound-page mock
 - pip install git+https://github.com/KurtJacobson/sphinx-gitstamp@MoreInfo
 - pip install --upgrade setuptools
 - sudo apt-get install pyqt5-dev-tools

docs/source/404.rst

@@ -0,0 +1,10 @@
+:orphan:
+
+===========================
+ 404 Error - Page Not Found
+===========================
+
+The requested page has either moved, or does not exist.
+Please try using the links from the sidebar to find what you are looking for.
+
+If you think this page *should* exit, please contact one of the site administrators or open an issue on GitHub.

docs/source/conf.py

@@ -42,11 +42,14 @@
     'sphinx.ext.githubpages',
     'sphinx.ext.napoleon',
     'sphinx_gitstamp',
+    'notfound.extension',
 ]
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
 
+notfound_urls_prefix = ""
+
 # The suffix(es) of source filenames.
 # You can specify multiple suffix as a list of strings:
 #