Add support for Metro testrun (#47)

And we have support for Metro testruns.

I added support for the Metro Application ID and created a new section (based on the Functional testrun).
 - I took out all OS information from the Filters since it doesn't make any sense here

You can see it on the sandbox server:
http://mozmill-sandbox.blargon7.com/#/metro/reports

@whimboo please review. Thanks.