Update CBT to support RBD Erasure Coding testing

CBT current does not support testing RBD Erasure coding (ceph 12.2.2). ceph.py needs to be updated such that when librbdfio.py calls mkpool with a data pool specified ceph.py uses the data_pool_profile instead of the pool_profile.

Since librbdfio will append "-data" to the pool name if a user had specified a data_pool the below could be a possible solution.

cbt/cluster/ceph.py:
def mkpool(self, name, profile_name, application, base_name=None):
if 'data' in name:
pool_profiles = self.config.get('data_pool_profiles', {'default': {}})
else:
pool_profiles = self.config.get('pool_profiles', {'default': {}})
. . .