Add sphinx version warning package

docs/.readthedocs.yml

@@ -0,0 +1,10 @@
+version: 2
+
+python:
+  version: 3.7
+  install:
+    - method: pip
+      path: .
+      extra_requirements:
+        - sphinx-version-warning
+

docs/conf.py

@@ -26,7 +26,14 @@ import sys
 
 # Add any Sphinx extension module names here, as strings. They can be extensions
 # coming with Sphinx (named 'sphinx.ext.*') or your custom ones.
-extensions = []
+import versionwarning
+version = release = versionwarning.version
+versionwarning_messages = {
+    'latest': 'These are the old docs for RAPIDS beta. Got to <a href="https://www.rapids.science">https://www.rapids.science</a> for the latest',
+}
+versionwarning_banner_title = 'Deprecated Version'
+versionwarning_body_selector = 'div[itemprop="articleBody"]'
+extensions = ['versionwarning.extension']
 
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ['_templates']
@@ -120,7 +127,7 @@ html_theme = 'sphinx_rtd_theme'
 # Add any paths that contain custom static files (such as style sheets) here,
 # relative to this directory. They are copied after the builtin static files,
 # so a file named "default.css" will overwrite the builtin "default.css".
-html_static_path = ['_static']
+# html_static_path = ['_static']
 
 # If not '', a 'Last updated on:' timestamp is inserted at every page bottom,
 # using the given strftime format.