- added unit tests for apply functions
- added another json config file for this
- 100% code coverage reached

- added test cases for test_apply, testing for basic create, update, delete records
- added previous state json file in test/fixtures to do the above

- added test cases for testin populate()
- added mock request responses in tests/fixtures/
- updated requirements.txt to require edgegrid-python

`Included` and `Excluded` can be used to filter records for one or more specific provider(s). This can be extremely useful when certain record types are not supported by a provider and you want only that provider to receive an alternative record.

See also: https://github.com/github/octodns/issues/26