add custom metrics
Added Segmentio provider

Added Segmentio (server-side only) as an analytics provider
Removed testing/debugging code
Mentioned Segmentio provider in changelog
Merge pull request #103 from wka/master

Addded Segment.io (server-side only) as an analytics provider
Update Podfile
add librato stubs to the app, and should bring us back to green
fix header docs
Merge pull request #102 from briomusic/GAI_customMetrics

add custom metrics
version bump to 2.8.0