Try to run the spellchecker on travis
diff --git a/docs/conf.py b/docs/conf.py
index 0066031..a42dcb2 100644
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -38,6 +38,7 @@
     'sphinx.ext.intersphinx',
     'sphinx.ext.viewcode',
     'cryptography-docs',
+    'sphinxcontrib.spelling',
 ]
 
 # Add any paths that contain templates here, relative to this directory.