mock out external libs when buildings docs

Author: phobson

docs/conf.py

@@ -17,6 +17,12 @@
 import os
 import shlex
 
+import mock
+ 
+MOCK_MODULES = ['numpy', 'scipy', 'matplotlib', 'matplotlib.pyplot', 'scipy.stats']
+for mod_name in MOCK_MODULES:
+    sys.modules[mod_name] = mock.Mock()
+
 # If extensions (or modules to document with autodoc) are in another directory,
 # add these directories to sys.path here. If the directory is relative to the
 # documentation root, use os.path.abspath to make it absolute, like shown here.