Update CloudEnvironment.php

Per email discussion: added dot between sitegroup and environment (instead of concatenation)
Fixed testGetDefaultCredentialsFilepath, concat issue
Merge pull request #56 from daphneacquia/05272014_Bug_Fix

Invalid path to credentials file on production environments, attempt 2
PSR-2 fix.
Prepare for 0.10.2 release.
Post 0.10.2 release.