Add  create and delete to Jumpgate volume API

    1. Support SL portable storage create operation via jumpdate
    2. Support SL portable storage delete operation via jumpdate
    3. Add unittest coverage for jumpgate volume create/delete

Change-Id: I9cd6acb0832279fdfa5080e728ecaef9ac9de638
@sudorandom 
Yes. I have been doing monkey_patch in the openstack nova/cinder code before. And you are
right, eventlet is one of the python3 incompatible module. None of the openstack core service are python3 compatible(https://wiki.openstack.org/wiki/Python3 and this is the effort https://wiki.openstack.org/wiki/Python3/SprintPycon2014)

The current code that poll the volume create status is not very scalable. But it shouldn't  have
consistency issue. Do you think we can agree on the volume create/delete and leave the
scalability issue as separate task.  I have some some modification of current commit. Will deliver another patch set. 

Thoughts?