Django-letsencrypt

- Internal Changes
- Removed the need to render `ACME` responses through a template. Instead
responses are now passed through a `HttpResponse` with a `content_type` of
`text/plain`. Thanks to [Peter Curet](https://github.com/petercuret)
for providing a pull request.
- [GH-29](https://github.com/urda/django-letsencrypt/pull/29)
- [GH-30](https://github.com/urda/django-letsencrypt/pull/30)
- Corrected `Copyright` dates across the project
- Thanks to Contributors:
- [Peter Curet](https://github.com/petercuret)

- Project Changes
- Admin `ordering` for the Django admin page is now down by `challenge`
- Removed `created_ts` and `updated_ts` from model
- Switched `challenge` and `response` from `TextField` to `CharField`
- Internal Changes
- Added testing for `detail` view for `ACME` objects
- Removed `migrations.py` thanks to existing `example_project`'s manage.py

- Project Changes
- Require `pytz` for SQLite users.
- Update `travis` branch build targets.

- Project Changes
- Final "feature" release of the 1.x branch. 2.0 will support `mysql`.
This had to be done due to certain model upcoming model changes, and
will result in a new set of migrations.

- Internal Changes
- Started using `twine`
- Started uploading `bdist_wheel`

- Internal Changes
- Start using `--sign`, such as: `python setup.py sdist upload --sign -r pypi`