Trytravis

Fixed

- Issue where `committed_at` would not be normalized to UTC. 18 Reported by einball

Changed

- Can no longer use a repository without containing the name `trytravis`.
This is to prevent accidentally using a repository the user didn't intend
to call with `git push -f`.

Fixed

- Issue where if `env` isn't defined in `.travis.yml` then the
script will error out with `KeyError`. 12 Reported by eeeebbbbrrrr.

Added

- Better message when running from a non-git repository.

Fixed

- When running multiple times with the same commit hash `trytravis` would sometimes
find and watch the incorrect build.
- `trytravis` would display an HTTPS URL even if an SSH URL was used in the output.

Added

- Added the ability to read your repository slug from the local config.
- Added ability to add repository directly via command line with --repo option.
- Added the main functionality to trigger and watch Travis builds.
- Added ability to use `ssh://gitgithub.com/[USERNAME]/[REPOSITORY]` formatted remote urls.

Changed

- Flattened the structure of all functions. Adhered to PEP8.