Add Task tests and Filter tests.
Add missing docs.
Add tests for non-class and filter tests.

* Includes stubs for future test cases
* Includes testing for generate_templates, send_email, and
  write_rendered_files.
Add tests for Section.
Add tests for AsanaAPI.
Add testcase for when smtplib.sendmail fails.
Move CLI parser creation into its own function.
Add project test cases and fixes.
Add tests for main function.
Merge branch 'testing'

Fixes #1.