Add barebones testing framework.

* run.py sets up and configures the testing environment
  and runs the test suite.
* test_requirements.txt provides packages needed to run
  the tests locally.
* tests.py contains one dummy test, which currently
  fails because of insufficient parameters in send()
  (which at least means no ImportErrors).
* A new Makefile target ties it all together.
Add coverage, and make the dummy test pass.

* This requires the coverage package and a new Makefile
  target.
* The coverage report doesn't show unless the tests pass,
  so add a dummy template to avoid getting errors from
  send().
* Add a .coveragerc file to ensure the coverage report
  displays only relevant information.
Fill in all the email tests.

* Test the default from email functionality.
* Test two fully featured emails, one an EmailMessage,
  one an EmailMultiAlternatives.  These are generated
  by the two branches of the if/else near the bottom
  of incuna_mail.send().
* This brings the coverage up to a mighty 87%.
Add a test for get_manager_emails.

* The test checks for existing users, doesn't find any,
  and falls back on a value in the settings.
* This method needs a database, so our list of requirements
  expands.
* Adding this test brings coverage to 100%!
Add .travis.yml.
Poking Travis.
Pip syntax fail.  Fix it!
More pip/yaml syntax fixes.
Rename test file for clarity.
Move test-specific settings into the tests.

* The 'with' statement allows us to put settings for a
  particular test into the specific test depending on
  them.  This is much better and cleaner than doing it
  in run.py.
Add discover-runner for Django<1.6.
Remove Django 1.4 for now.
Experiment with Python 3...

* Also use 'make coverage' in an attempt to get Coveralls
  to work.
Use None instead of [] to empty the outbox.

* Add an explanatory comment as well.
Add Python 3.3 on top of 3.4.
Remove apparently-unnecessary tearDown() method.
Merge pull request #5 from incuna/i5-add-tests

Add tests