(PUP-3019) Make PMT check for string status codes when downloading

Previously PMT was checking for integer status codes when downloading
modules. This results in all module downloads failing. After this PMT
will check for string status codes when downloading modules.
Merge pull request #2945 from adreyer/PUP-3019

(PUP-3019) Make PMT check for string status codes when downloading
Merge branch 'master' into puppet-4