Avoid hardcoding version in docs.

docs/conf.py

@@ -15,6 +15,7 @@
 
 import sys
 import os
+import pkg_resources
 
 # 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
@@ -59,9 +60,9 @@ copyright = '2015, Uli Fouquet'
 # built documents.
 #
 # The short X.Y version.
-version = '0.1.dev0'
+version = pkg_resources.get_distribution('diceware').version
 # The full version, including alpha/beta/rc tags.
-release = '0.1.dev0'
+release = version
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.