Add simple .gitignore file

This was suggested by:
http://python-packaging.readthedocs.io/en/latest/minimal.html

Signed-off-by: David A. Wheeler <dwheeler@dwheeler.com>

.gitignore

@@ -0,0 +1,15 @@
+# Ignore some files
+# Compiled python modules.
+*.pyc
+
+# Setuptools distribution folder.
+/dist/
+
+# Python egg metadata, regenerated from source files by setuptools.
+/*.egg-info
+
+# Don't distribute test results, since they get regenerated
+/test-results*
+
+# We may create tarballs, don't include those
+/*.tar.gz