3.0.0

bump version to 2.1.0

Merge pull request #67 from opentok/no-globals

remove window.rtcstats global

Merge pull request #58 from opentok/safari

safari: dont call chrome legacy stats

Merge pull request #57 from opentok/no-getstats-edge

edge: dont query getStats

Merge pull request #52 from opentok/module

add module version of rtcstats