Adapt to new Blazar state machine

[priteau]

The lease states in the latest version of Blazar have changed: see [1]. Also the 'action' field is no more.
The code at [2] needs to be adapted to the new states.

[1] https://docs.openstack.org/blazar/latest/user/state-machines.html
[2] https://github.com/SciDAS/kinc-chameleon/blob/master/kinc-chameleon.py#L65-L72