tests: ported test_system_take to WebDriver

Change-Id: Ia3b4876ee15b94a8e0acd072dfe319cbf97e1be3
clean up Take/Provision Now/Schedule Provision mess

Take/Return and immediate provisioning are only permitted if the system
is set to Manual. Otherwise, the system can only be reserved or
provisioned through the scheduler.

Bug: 855333
Change-Id: Ie5a5c7301ecf17ee9d881ae1fccc546524d81801
Merge changes Ie5a5c730,Ia3b4876e into develop

* changes:
  clean up Take/Provision Now/Schedule Provision mess
  tests: ported test_system_take to WebDriver