Simperium Mk 0.7.0

### Release Details:

- Issue #9: Added new primitives to retrieve the Synchronization Status.
- Issue #302: Updated SPCoreDataStorage to handle duplicate simperiumKey's across buckets.
- Issue #351: Fixed a bug in the networkEnabled setter.
- Issue #354: Rebased objects are now being marked for further processing.
- Issue #356: Fixed a race condition that caused batch changes not to get processed.
- Issue #359: Fixed a bug in SPManagedObject that caused updated fields not to get persisted.
- Issue #361: Updated SPChangeProcessor error logs. Treating changes for nuked entities is now a warning.