Add support for SQLAlchemy 1.0.4

This has been released and Gertty works with it.  A subsequent
change will accomodate SQLA 1.0.4-specific behavior.

Change-Id: I864c913354a8e69f0cfc68634c6ce081dce6eb3f

requirements.txt

@@ -1,7 +1,7 @@
 pbr>=0.6,!=0.7,<1.0
 
 urwid>=1.2.1,!=1.3.0
-SQLAlchemy>=0.9.4
+SQLAlchemy>=1.0.4
 GitPython>=0.3.2.RC1
 python-dateutil
 requests>=2.5.3,<3.0.0