Merge pull request #4 from rajeshrhino/master

Custom group/fields to save Mailchimp details
do api tests on api-key screen
Merge pull request #5 from deepak-srivastava/api-key-save-test

do api tests on api-key screen
sync contacts per group custom settings + a utils helper file
Merge pull request #6 from deepak-srivastava/queue-sync

sync contacts per group custom settings + a utils helper file
sync mapping schema changes
Merge pull request #7 from deepak-srivastava/sync-schema

sync mapping - schema changes
Merge remote-tracking branch 'upstream/master' into group-mailchimp-settings
Fixes for - Populate Custom List ID and Group options via apis