Ignore any egg and egg-info directories

Running the tests installs pbr in a way that leaves a .egg directory in
the source tree, so update the ignore file to ignore it.

Change-Id: I7d702c9511992efc518195def0967bc0191d93a9

.gitignore

@@ -6,7 +6,8 @@ ChangeLog
 *.log
 .tox
 .coverage
-oslo.messaging.egg-info/
+*.egg-info/
+*.egg
 build/
 doc/build/
 doc/source/api/