started group status filtering
predicate_all function
filtering disabled groups - not tested
Merge branch 'add2cloud-metrics' into group-status-filter
correct predicate_all impl with tests
using predicate_all in get_scaling_group

added tests for group_pred and props arg also
Merge branch 'master' into group-status-filter
IsCallable class

Can be used in tests to check if argument passed is callable
correcting call to get_scaling_group_servers

`get_scaling_group_servers` changed its arg to server_predicate but its
caller in metrics.py was not changed. Now changed it. Also updated tests
to check this
s/stauts/status + tests
Merge branch 'master' into group-status-filter

Conflicts:
	otter/metrics.py
	otter/test/test_metrics.py
using toolz.identity function
status column comma plus adding migration
predicate_all simpler impl - thanks @lvh
Merge pull request #717 from rackerlabs/group-status-filter

AS-394: Filter incorrect groups