Some fixes in the simulator
1. Fixed JSON response deserialization. While creating a mock a JSON can be passed which will be deserialized into a response object and returned from agent layer.
For e.g. for a mock corresponding to StopCommand, a response like "{"com.cloud.agent.api.StopAnswer":{"result":false,"wait":0}}" can be passed.
2. Ability to mock PingCommand (returned as part of getCurrentStatus() agent method). As a part of this a mocked VM state report can be returned.
For e.g. {"com.cloud.agent.api.PingRoutingWithNwGroupsCommand":{"newGroupStates":{},"newStates":{},"_hostVmStateReport":{"v-2-VM":{"state":"PowerOn","host":"SimulatedAgent.e6df7732-69b2-429b-9b6a-3e24dddfa2e0"},"i-2-5-VM":{"state":"PowerOff","host":"SimulatedAgent.e6df7732-69b2-429b-9b6a-3e24dddfa2e0"}},"_gatewayAccessible":true,"_vnetAccessible":true,"hostType":"Routing","hostId":3,"contextMap":{},"wait":0}}