(HI-129) Add ability to specify output format

This adds the ability to specify the output format from the hiera
command line. Supported formats are "ruby" (the default) and "json".
(HI-129) Add doc stating supported formats
Merge branch 'pr-172'

* pr-172:
  (HI-129) Add doc stating supported formats
  (HI-129) Add ability to specify output format
(Maint) Include json in the acceptance deps

Since puppet started depending on json, hiera tests need to make sure
that it is there.
(packaging) Update VERSION to 1.3.1
Merge tag '1.3.1'

1.3.1

* tag '1.3.1':
  (packaging) Update VERSION to 1.3.1
(RE-816) Add initial support for building in a RHEL 7 mock

Building in an x86_64 mock, since RHEL has not provided a 32-bit release.
Merge pull request #173 from mckern/add-el7-for-mocks

(RE-816) Add initial support for building in a RHEL 7 mock
(Maint) Colorize output when running specs on windows

Previously, running `bundle exec rspec spec` would output ANSI escape
sequences on windows. This commit adds a dependency on win32console, and
updates the spec_helper to use it.
(HI-186) Express Windows specific gem dependencies

Previously, if a ruby module on windows tried to use hiera as a library,
the calling module had to know about hiera's platform specific
dependencies. This comes up when trying to develop and test puppet
modules on windows.

This commit adds the windows specific gems to project_data.yaml, and
updates the Gemfile to add these dependencies when during
`bundle install`

The build pipeline will automatically create an x86-mingw32 gem in
addition to the generic one.
Merge branch 'pull-171'

This closes GH-171