Welcome to the new contributors: @ocefpaf and @tonyfast!

Changes:

* Fix encoding bug on Windows
[#24](https://github.com/ericdill/depfinder/pull/24)
* Provide support for namespaced packages and move all package name
mappings to a data file
[#23](https://github.com/ericdill/depfinder/pull/23)
* Start having some serious discussions around python 3.7 compatibility
in depfinder [#20](https://github.com/ericdill/depfinder/issues/20)