v0.1.13

Read and store origin url when adding repo

* add Git trait abstraction and inject
* add test coverage for read/write url
* remove old unit test that's now covered with integration test
* update test.sh for remotes

I'm not super-happy with the toml layout, but the format I designed
isn't supported by toml.rs yet - see https://github.com/alexcrichton/toml-rs/issues/406