Throw deprecation warnings for these imports, which will be removed in the next version. They've been deprecated for two years so we can make it happen.
Settings conf - rename `ARMSTRONG_RENDER_MODEL_BACKEND` to `ARMSTRONG_LAYOUT_BACKEND` to better reflect its purpose.
Rename `BasicRenderModelBackend` to `BasicLayoutBackend` and throw DeprecationWarnings.
Use older style string formatting for Python 2.6
Support testing under Python 2.6. Modify TravisCI config.
Fix testing in Django 1.6 by using the old test runner.
Organization tweaks and document removal in version 2.0 (not 1.4).
Warnings refer to the calling location.
Tests - don't use our deprecated `get_layout_template_name`.
Merge pull request #16 from joncotton/deprecations

#16 more sensible names, raise deprecation warnings, testing in Python 2.6