(PUP-1151) Consolidate JSON schema validation

This adds a new matcher to the JSONMatchers to validate json against a
given json-schema. All of the json schema validation now goes through
this one matcher, which also handles skipping the checks on windows.
Merge pull request #2259 from zaphod42/feature/master/pup-1151-environment-enumeration

(PUP-1151) Consolidate JSON schema validation
(pup-923) Add a fedora 20 config
(PUP-1151) Convert to cygwin paths on windows

The curl command on windows doesn't handle windows path (C:\foo\bar), so
we need to convert these to posix paths using cygpath.
Merge branch 'feature/master/pup-1151-environment-enumeration'

* feature/master/pup-1151-environment-enumeration:
  (PUP-1151) Convert to cygwin paths on windows
(maint) Fix unused argument and variable in file_spec.rb
Merge pull request #2260 from glennpratt/patch-1

(maint) Fix unused argument and variable in file_spec.rb