Murano environment deletion hangs for 1 hour

https://bugs.launchpad.net/murano/+bug/1576703

Detailed bug description:
Murano environment deletion hangs for 1 hour.
All instances are removed almost immediately.
Murano environment stays in deleting status after page reload and after relogin in Murano dashboard.

Steps to reproduce:
        1. Create Murano environment
        2. Add Kubernetes Cluster application to the environment: Set
        initial_gateways=1, max_gateways=2, initial_nodes=1, max_nodes=2
        3. Add Kubernetes Pod to the environment
        4. Add some application to the environment
        5. Deploy environment
        6. Check deployment status and make sure that all nodes are active
        7. Execute scaleNodesUp action and wait deployment is finished
        8. Check deployment status and make sure that all nodes are active
        9. Delete Murano environment

Expected results:
  1-8 OK, deployment is finished without errors
  9. OK, Murano environment is deleted in several minutes

Actual result:
  1-8 OK, deployment is finished without errors
  9. NOK, Murano environment hangs in deleting status during 1 hour.
  In Deployment Logs (murano dashboard) appears incorrect message:
   2016-04-04 14:03:33 — Action None is scheduled
                After 1 hour, environment is removed from the environment list.
                Error message 'Unable to retrieve list of deployments' appears in Murano dashboard.

Reproducibility:
often

Description of the environment:
MOS 8.0
1 controller node
1 compute node

VERSION:
  feature_groups:
    - mirantis
  production: "docker"
  release: "8.0"
  api: "1.0"
  build_number: "570"
  build_id: "570"
  fuel-nailgun_sha: "558ca91a854cf29e395940c232911ffb851899c1"
  python-fuelclient_sha: "4f234669cfe88a9406f4e438b1e1f74f1ef484a5"
  fuel-agent_sha: "658be72c4b42d3e1436b86ac4567ab914bfb451b"
  fuel-nailgun-agent_sha: "b2bb466fd5bd92da614cdbd819d6999c510ebfb1"
  astute_sha: "b81577a5b7857c4be8748492bae1dec2fa89b446"
  fuel-library_sha: "c2a335b5b725f1b994f78d4c78723d29fa44685a"
  fuel-ostf_sha: "3bc76a63a9e7d195ff34eadc29552f4235fa6c52"
  fuel-mirror_sha: "fb45b80d7bee5899d931f926e5c9512e2b442749"
  fuelmenu_sha: "78ffc73065a9674b707c081d128cb7eea611474f"
  shotgun_sha: "63645dea384a37dde5c01d4f8905566978e5d906"
  network-checker_sha: "a43cf96cd9532f10794dce736350bf5bed350e9d"
  fuel-upgrade_sha: "616a7490ec7199f69759e97e42f9b97dfc87e85b"

Scrinshot: https://drive.google.com/a/mirantis.com/file/d/0Bz15vbpS5ZPNUUVwQTlPZEltdkU/view?usp=sharing
Snapshot: https://drive.google.com/a/mirantis.com/file/d/0Bz15vbpS5ZPNSWJ1b2lhcmZhYjQ/view?usp=sharing
murano-api.log: https://drive.google.com/a/mirantis.com/file/d/0Bz15vbpS5ZPNV1BHUHlDS2cxTTQ/view?usp=sharing
murano-engine.log: https://drive.google.com/a/mirantis.com/file/d/0Bz15vbpS5ZPNNHY0aXpURUFtTGs/view?usp=sharing