Task's state and get task by node improved

Has been improve the CLI to have into account
the node level at the moment to get a task and
perform a delete operation over it, also has been
updated the task's state to get due to the change
made in the API.

Bug: STACKOPHEAD-497
Task 'cancel' ans 'state' improved at node level

Has been modified the RESTful requests for
'cancel' and 'state' in automation therefore must be
updated the client. Related with pull request
https://github.com/StackOps/stackops-head/pull/23

Bug: STACKOPHEAD-498
Merge pull request #4 from StackOps/bug/stackopshead-498

Bug/stackopshead 498