Merge pull request #1115 from python-cmd2/fix_manifest

Exclude plugins directory from tarball when cmd2 release is published

Author: tleonhardt

MANIFEST.in

@@ -3,4 +3,5 @@ recursive-include examples *
 recursive-include tests *
 recursive-include docs *
 recursive-exclude docs/_build *
+recursive-exclude plugins *
 exclude .github .gitignore azure-pipelines.yml tasks.py