(maint) Parse PMT JSON output when testing

JSON hash structures are unordered and when testing the output of the
puppet module tool the output was assumed to be ordered. This commit
extracts the outputted JSON and converts it into a Ruby data structure
and performs checks on the data elements to ensure the output is
correct.
Merge pull request #1499 from adrienthebo/parse-pmt-json-output

(maint) Parse PMT JSON output when testing