releasing 0.6.4 with updated libs
guards against unfinalized statements when multiple payload database are created and are unsynchronized, fixes #25
updating to Viewed X Screen new spec, fixes #28
updating countly version to fix null pointer exception, fixes #27
updated flushing thread to remove from the db first, try sending, and requeue only if it didn't work, fixes #24
Merge branch 'master' of https://github.com/segmentio/analytics-android