Substrate filter rules

Substrate filter rules

As a slightly most testable impl of Marco's work I'm offering this as a
counter proposal. Happy to talk through the thought process.

https://code.launchpad.net/~bcsaller/charm-tools/test-cfg/+merge/200959

(do not edit description out of merge proposal)

[bcsaller, 2014-01-09 07:49:51]

Please take a look.

[Marco Ceppi, 2014-01-09 15:27:24]

This is an interesting concept of defining order and making it explicit. I
didn't quite grasp it until I saw the unit tests for it. I'm not opposed to it
now, test.py:652 is still a concern but my comment on 473 now no longer applies

https://codereview.appspot.com/49670043/diff/1/charmtools/test.py
File charmtools/test.py (right):

https://codereview.appspot.com/49670043/diff/1/charmtools/test.py#newcode473
charmtools/test.py:473: 'order should be defined using only include and skip')
Isn't it counter intuitive to have both include and skip? By design if you only
have an `include` key it'll skip everything not in that include key. Likewise,
if you have a skip it's understood that you'll do everything but. Seems this
should just be OR

https://codereview.appspot.com/49670043/diff/1/charmtools/test.py#newcode652
charmtools/test.py:652: rules = parse_substrates(cfg)
This wouldn't work as cfg is a TestCfg object that only has everything in the
'options' key. Substrate data would be in 'substrates' at the same level of
'options'. So if parse_substrates took the test_plan file and did a parsing that
would work. Alternatively TestCfg could (should?) parse what's in substrates and
store it as part of the object so you can just pass cfg as you're doing here
instead of re-parsing the test_config.yaml file