CFY-1215: Add volume create/delete implementation
CFY-1215: Add volume attach/detach implementation
CFY-1215: Update plugin template
CFY-1215: Add unit tests

Add nominal unit tests for volumes operations.
Fix issues discovered by unit tests.
CFY-1215: Fix issues found by manual tests

Fix issues discovered by manual tests.
Update unit tests.
CFY-1215: Address pull request comments
CFY-1215: Fix _get_volume_by_name

Use volume.display_name instead of volume.name
CFY-1215: Address Ran Ziv comments

Fix the code.
Update unit tests.
added licenses
fixed transformation of volume display name
merge commit from master
fixed get_resource_id usage
added openstack name runtime property to volume type; refactored delete method and extended sugared cinder client
removed attached_to relationship type
fixed 'cinder_config' into 'openstack_config'
added with_neutron_client / with_nova_client with a check if it already appears in kwargs
fixed get name of cinder sugared client
removed volume device name from runtime properties, will now appear in properties'
'
refactored with_xxx_client usage
refactored use_external_resource method