Primary Key Support (To Fix Deletion)

[sethdenner]

• Deletion depends on more robust primary key support. We were running into issues where unexpected rows were being deleted. This was caused by django matching just one field of the primary key (the one defined as primary_key=True). I implemented a new PrimaryKey field to handle this correctly. Calling .pk on a model now returns a PrimaryKeyValue object which is an OrderedDict subclass containing the key/values of the partition keys and the clustering keys.
• Modified denormalization tests to catch the above unexpected deletion issue.
• Added a new DateTimeField that truncates the nanoseconds off of date time since Cassandra doesn't support nanoseconds.
• Updated version string to minor revision 0.7.0

[coveralls]

Coverage increased (+0.3%) to 66.452% when pulling 68372efda477a6a40674e6cae4f6ae38eb0e47e4 on sethdenner:primary-key-support into 6f13c59b4b6e2e2846fbc5e2ab159d497af6aa03 on Knotis:master.

[coveralls]

Coverage increased (+0.3%) to 66.476% when pulling 68372efda477a6a40674e6cae4f6ae38eb0e47e4 on sethdenner:primary-key-support into 6f13c59b4b6e2e2846fbc5e2ab159d497af6aa03 on Knotis:master.