Include version string automatically in documentation

doc/conf.py

@@ -51,9 +51,10 @@ copyright = u'2009, Tiago de Paula Peixoto <tiago@forked.de>'
 # built documents.
 #
 # The short X.Y version.
-version = '2.0'
+from graph_tool import __version__ as gt_version
+version = gt_version.split()[0]
 # The full version, including alpha/beta/rc tags.
-release = '2.0beta1'
+release = gt_version.split()[0]
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.