Add *.swp to gitignore.

Add swap files and alphabetize the list.

Change-Id: Idaa9aec831740aa965a8d2d2486f4d9ffbb50746

.gitignore

@@ -1,24 +1,25 @@
-AUTHORS
-Authors
-ChangeLog
-*.pyc
 *.DS_Store
-local_settings.py
-CA/
-keeper
-instances
-keys
-build/*
-build-stamp
-cinder.egg-info
-.cinder-venv
-.venv
-.tox
-*.sqlite
 *.log
 *.mo
-tools/conf/cinder.conf*
-cover/*
-dist/*
+*.pyc
+*.sqlite
+*.swp
+.cinder-venv
 .coverage
+.tox
+.venv
+AUTHORS
+Authors
+build/*
+build-stamp
+CA/
+ChangeLog
+cinder.egg-info
+cover/*
 covhtml
+dist/*
+instances
+keeper
+keys
+local_settings.py
+tools/conf/cinder.conf*