Ensure missing period is treated consistently

Add a new test to ensure that all of the storage drivers
return a consistent value for the period.

Fix the SQLAlchemy driver so it returns 0 for the period
if no period is provided in the input to the query.

Change-Id: I3bc272aea1fd1ce29953d2080b58d75f5373513a
Signed-off-by: Doug Hellmann <doug.hellmann@dreamhost.com>
Merge "Ensure missing period is treated consistently"
HBase storage driver, initial version.

This is a new storage driver that supports storing of Ceilometer
data in an HBase backend. This version does not have metaquery
support yet.

Implements: blueprint hbase-storage-backend
Change-Id: Id3e7ec01434b1be30cce4f91b39461fc389a000f
Merge "HBase storage driver, initial version."