Cleanup .gitignore

Per Henry's comments here [1], lets clean this up so it looks
nice and fancy like Neutron's .gitignore.

[1] https://review.openstack.org/#/c/247855/

Change-Id: Ie843eedc19fff5a0a4c342617c83093aa2cfbcbf
Signed-off-by: Kyle Mestery <mestery@mestery.com>

.gitignore

@@ -1,54 +1,27 @@
-*.py[cod]
-
-# C extensions
-*.so
-
-# Packages
-*.egg
-*.egg-info
-dist
-build
-.eggs
-eggs
-parts
-bin
-var
-sdist
-develop-eggs
-.installed.cfg
-lib
-lib64
-
-# Installer logs
-pip-log.txt
-
-# Unit test / coverage reports
-.coverage
-.tox
-nosetests.xml
-.testrepository
-.venv
-
-# Translations
-*.mo
-
-# Mr Developer
-.mr.developer.cfg
-.project
-.pydevproject
-
-# Complexity
-output/*.html
-output/*/index.html
-
-# Sphinx
-doc/build
-
-# pbr generates these
 AUTHORS
+build/*
+build-stamp
 ChangeLog
-
-# Editors
+cover/
+covhtml/
+dist/
+doc/build
+*.DS_Store
+*.pyc
+neutron_lib.egg-info/
+neutron_lib/vcsversion.py
+neutron_lib/versioninfo
+pbr*.egg/
+releasenotes/build
+setuptools*.egg/
+*.log
+*.mo
+*.sw?
 *~
-.*.swp
-.*sw?
+/.*
+!/.coveragerc
+!/.gitignore
+!/.gitreview
+!/.mailmap
+!/.pylintrc
+!/.testr.conf