Code review comment for lp:~chad.smith/charms/precise/block-storage-broker/bsb-ec2-support

Thanks for the reviews guys:

dpb[0 & 1]:
- test isolation and makefile fixes have been made to ensure -j3 is run during unit tests. had to drop global mocker.replace("path.to.module") and instead mock.patch local methods/functions to avoid collisions with running in multiple threads

[2] trusty failures:
- they are resolved in a followon MP: at https://code.launchpad.net/~chad.smith/charms/precise/block-storage-broker/bsb-trusty-support/+merge/211963

dpb[3] in StrogaeServiceUtil.__init__, the environment needs to be loaded
before:

    self.ec2_instances_command = getinstances.DescribeInstances()
    self.ec2_volumes_command = getvolumes.DescribeVolumes()

  - Resolved in this branch to actually call DescribeVolumes() and DescribeInstances() during _ec2_describe_volumes and _ec2_describe_instances respectively so that we ensure load_environment is called 1st. importing these classes directly from euca2ools is a no-no and broke us on trusty. The trusty support branch mentioned about drops these imports completely in favor of parsing the euca commandline tool output.