Enable integration tests again.

Enable integration tests again.

Other changes:

  * manager/config
    * Describe required YANG models and applications in capabilities.
  * manager/it/option
    * Load inventory-manager and topology-manager.
    * Don't load forwardingrules-manager because it is unnecessary for
      VTN Manager.
  * Fixed several bugs in integration test modules.
    * Don't send any notification after tests.
    * Ensure that node-connector is created before notifying link
      discovery because topology-manager will remove links on newly
      created node-connector.
    * VTNManagerIT.testRoutingTable(): Synchronize packet processing
      before solving path faults.

Change-Id: I947419324932a38adcdf060211f8643a64da82e1
Signed-off-by: Shigeru Yasuda <s-yasuda@da.jp.nec.com>