Update Makefile

Add a new 'help' recipe to the Makefile. Make this recipe the default. This
recipe lists out all available recipes and gives a brief description of their
effects.

Add a new 'test-docstrings' recipe to the Makefile. This recipe calls
`testimony`, just as Travis does right now.

Update the `.PHONY` special target. Wrap the line so as to be readable on
narrower editors.

Add comments to the makefile to visually separate its sections.
Make .travis.yml less special

Remove the `testimony validate_docstring ...` commands from `.travis.yml`.
Instead, make Travis call a functionally equivalent command in the Makefile.

Do not install any Python packages directly from `.travis.yml`. Instead, update
`requirements-optional.txt` and make travis install the modules listed therein.
some fixes for the org test cases
Merge pull request #930 from kbidarkar/fix-org-tests-jun26

some fixes for the org test cases
Merge pull request #931 from Ichimonji10/refactor-tooling

Refactor tooling
Add method `get_server_credentials`

New method simply returns a tuple of ('username', 'password'). It's simple, but
more convenient than reading values from the config incrementally. Also, add
unit tests for the new method.
Create some simple tests for path api/v2/hosts

Implement a few tests which check whether it's possible to GET or POST to the
path. Check for things like whether an HTTP 200 is generated when a GET request
is issued, that sane sets of data are returned, and that an HTTP 401 is
generated when an unauthorized HTTP request is made.
Decorate method with `skip_if_bz_bug_open`
Create some simple tests for path api/v2/models

Implement a few tests which check whether it's possible to GET or POST to the
path. Check for things like whether an HTTP 200 is generated when a GET request
is issued, that sane sets of data are returned, and that an HTTP 401 is
generated when an unauthorized HTTP request is made.