Need to add waiter for test upload_config_for_node_and_env_in_transitional_state

Description of the environment: fuel-10.0-289-2016-05-30

Steps to reproduce: run test upload_config_for_node_and_env_in_transitional_state

 Scenario:
            1. Revert snapshot "basic_env_for_reconfiguration"
            2. Add 1 compute
            3. Deploy changes
            4. Upload a new openstack configuration for env

            5. Check nailgun response ==> Nailgun accept the uploaded config

            6. Wait for added node in provisioning state
            7. Upload a new openstack configuration for node
            8. Check Nailgun response
            9. Wait for added node in deploying state
            10. Upload a new openstack configuration for node
            11. Check Nailgun response
            12. Wait for finishing of deployment

Expected results: test run successfully, no conf was uploaded
Actual result: Test uploaded yaml

https://product-ci.infra.mirantis.net/job/10.0.system_test.ubuntu.services_reconfiguration_thread_2/53/testReport/(root)/upload_config_for_node_and_env_in_transitional_state/

I've recheck this issue manually:

1. Add node to the cluser
2. Deploy cnhages
3. Upload config fot the whole cluster

And I got expected 404 error:

http://paste.openstack.org/show/506531/

Seems that test run the uploading too fast and no task was started at that time. I suppose that we need to add waiter that the env change the state to "deployment"