Carrry over group traits (to `identify`).
Updated according to review comments.
IE9- compatibility (`Object.keys` -> `empty`).
intercom: cache group, to prevent race conditions.
Merge pull request #127 from realyze/fix/intercom-race

Carrry over group traits (to `identify`).
fix intercom page to call update
Remove duplicate invalid bing ads link from Readme
swap curebit to load the iframe on #page, BREAKING TESTS
Merge pull request #130 from tonytaing/patch-1

Remove duplicate invalid bing ads link from Readme
fixing curebit tests, fixes #126
Merge pull request #132 from segmentio/fix/curebit-page

Fix/curebit page
Merge pull request #131 from segmentio/fix/intercom-page

fix intercom page to call update
Release 0.6.0
cleanup and re-structure.