A change is coming to Ansible where module params will default to str.
Many of our modules were taking advantage of this by not being explicit
about the type, so they will break when that change merges. This hopefully
catches those cases.
The exception message, when shade fails, will contain much more
specific information about the failure if the exception is treated
as a string. The 'message' attribute alone is usually not helpful.
The min_disk and min_ram parameters were not being passed to
the shade API. They also need to be integer values. Also
updated the description of these parameters for better
clarification.
