Added CI configuration
This commit adds a CI configuration for ligo-common, which does the following
- tests that the package builds for python 2.7, 3.4, 3.5, and 3.6
- builds tarball, universal wheel, rpm, and debs (debian 8 and 9)
- deploys to pypi
The final step of deployment to pypi only occurs for tags, and will require @adam-mercer to add the following variables to the secrets list for this repo
TWINE_USERNAME
TWINE_PASSWORD
as is done for lscsoft/lalsuite.