Code review comment for lp://qastaging/~bac/juju-quickstart/donde-brew

Reviewers: mp+223012_code.launchpad.net,

Message:
Please take a look.

Description:
Fail early if brew is not installed.

Did some refactoring to list required files for each supported platform.
If required files are not found, fail early with an appropriate parser
error message.

https://code.launchpad.net/~bac/juju-quickstart/donde-brew/+merge/223012

(do not edit description out of merge proposal)

Please review this at https://codereview.appspot.com/108930045/

Affected files (+105, -4 lines):
   A [revision details]
   M quickstart/manage.py
   M quickstart/platform_support.py
   M quickstart/tests/test_manage.py
   M quickstart/tests/test_platform_support.py