Initial working metrics impl - no tests

This fetches tenants and groups from CASS and servers from nova for all
these tenants and gives out total desired and total actual for a region
handling groups with 0 servers too

also minor code improvements
reactor as optional arg
Merge branch 'master' into metrics
moved get_scaling_group_servers to convergence.py
Started convergence tests

Modified method to take treq impl
minor clarity in code
Merge branch 'master' into metrics
StubTreq2 - an easier API with more functionality
get_all_server_details tests implemented
get_scaling_group_servers filtering change - thanks @cyli

removing status based filtering out of get_scaling_group_servers and added its tests
Merge branch 'master' into metrics

Conflicts:
	otter/convergence.py
	otter/test/test_convergence.py
Moved metrics.py in otter/

Also added tests for get_scaling_groups
metrics collection tests added

Split getting all metrics in separate function
Merge branch 'master' into metrics

Conflicts:
	otter/convergence.py
stdout print is optional

This way tests will not print on screen
shorter statement
get_scaling_groups returns list

instead of always grouping them based on tenant.
Also added function to print customers with Rackconnect setup
added function to check different configs
set of properties - thanks @cyli

to ensure same properties are not fetched from cass