Implement pipeline requirement on github reviews

Github reviews are a new pipeline requirement that is driver specific.
Reviews can be approved, changes_requested, or comment. They can come
from people with read, write, or admin access. Access is hierarchical,
admin level includes write and read, and write access includes read.

Review requirements model loosely the gerrit approvals, allowing
filtering on username, email, newer-than, older-than, type, and
permission.

Brings in an unreleased Github3.py code. Further extends that code to
determine if a user has push rights to a repository.

Documentation is not included with this change, as the docs need
restructuring for driver specific require / reject.

Change-Id: I3ab2139c2b11b7dc8aa896a03047615bcf42adba
Signed-off-by: Jesse Keating <omgjlk@us.ibm.com>
diff --git a/requirements.txt b/requirements.txt
index 9f20458..aeaabfa 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,8 @@
 pbr>=1.1.0
 
-Github3.py==1.0.0a2
+# pull from master until https://github.com/sigmavirus24/github3.py/pull/671
+# is in a release
+-e git://github.com/sigmavirus24/github3.py.git@develop#egg=Github3.py
 PyYAML>=3.1.0
 Paste
 WebOb>=1.2.3