Ensure that README file makes it into the tarball

setup.cfg depends on the README file for its long description, so if
it's not in the source tarball, the build will bomb out. README.rst is an
automatically grokked name of a file for python and gets included
automatically. While we're dealing with this, add a MANIFEST.in to
ensure that AUTHORS and ChangeLog get installed too.

Change-Id: Id59fa5a6fecc179a80710ba8a5dc898fb713b1cf

MANIFEST.in

@@ -0,0 +1,6 @@
+include AUTHORS
+include ChangeLog
+exclude .gitignore
+exclude .gitreview
+
+global-exclude *.pyc

setup.cfg

@@ -4,7 +4,7 @@ author = OpenStack
 author-email = openstack-dev@lists.openstack.org
 summary = Collect and cache metadata, run hooks on changes.
 description-file = 
-	README.md
+	README.rst
 home-page = http://github.com/stackforge/os-collect-config
 classifier = 
 	Development Status :: 4 - Beta