Automate building the Sphinx docs via 'tox'.

CHANGES.txt

@@ -4,7 +4,9 @@
 Unreleased
 ----------
 
-- Fix 'zconfig:' URIs under Python 2.7.  The code worked around a bug in
+- Automated building the Sphinx docs via ``tox``.
+
+- Fixed 'zconfig:' URIs under Python 2.7.  The code worked around a bug in
   the stdlib's 'urlparse.urlsplit' for Python < 2.7; that workaround broke
   under 2.7.  See https://github.com/Pylons/zodburi/issues/5
 

tox.ini

 [tox]
 envlist =
-    py26,py27,cover
+    py26,py27,cover,docs
 
 [testenv]
 commands =
@@ -21,3 +21,11 @@ deps =
 # combination of versions of coverage and nosexcover that i can find.
 # coverage==3.4 is required by nosexcover.
 
+
+[testenv:docs]
+basepython =
+    python2.6
+commands =
+    sphinx-build -b html -d docs/_build/doctrees docs docs/_build/html
+deps =
+    Sphinx