Made grocer version minimum required for passbook notifs

Grocer added passbook notifications for 0.3.0
https://github.com/grocer/grocer/commit/6d926ad9e7c5b7d03e5ca2b228bef4db640bc3db
Merge pull request #35 from NikoRoberts/patch-1

Made grocer version minimum required for passbook notifs