Remove version from setup.cfg

pbr won't let development versions install otherwise.

Also set up some build_sphinx configuration to mimic what Swift does.
This seems to be what's causing the lingering docs failure, though I'm
not sure why it wasn't a problem before.

Change-Id: I2e4c416a21d98d10377b7d2424bac93a139220fa

setup.cfg

@@ -1,6 +1,5 @@
 [metadata]
 name = swift3
-version = 1.11.0
 summary = Swift AmazonS3 API emulation Middleware
 description-file =
     README.md
@@ -31,6 +30,11 @@ paste.filter_factory =
     swift3 = swift3.middleware:filter_factory
     s3token = swift3.s3_token_middleware:filter_factory
 
+[build_sphinx]
+all_files = 1
+build-dir = doc/build
+source-dir = doc/source
+
 [nosetests]
 exe = 1
 verbosity = 2