Prepare the 1.1.0-rc7 release

1.1.0-rc7 (7/7/2016)
--------------------

  This release is a version bump to unblock people since our naming scheme does not match pip's
  expectations.  When doing a pip install pre and rc releases resolve to the same name so
  '1.1.0-rc0' is treated the same as '1.1.0-pre0'. A long term solution is being discussed on
  pants-devel.

Testing Done:
CI pending: https://travis-ci.org/pantsbuild/pants/builds/143202699

Reviewed at https://rbcommons.com/s/twitter/r/4055/

src/python/pants/version.py

@@ -8,6 +8,6 @@
 from pants.base.revision import Revision
 
 
-VERSION = '1.1.0-rc0'
+VERSION = '1.1.0-rc7'
 
 PANTS_SEMVER = Revision.semver(VERSION)