Error messages are absent for scaleNodesUp/Down and scaleGatewaysUp actions

Detailed bug description:
Error messages are absent for scaleNodesUp/Down and scaleGatewaysUp actions if maximum minions/gateways limit already reached.

Steps to reproduce:
        1. Create environment
        2. Add Kubernetes Cluster application to the environment: Set
        initial_gateways=1, max_gateways=1, initial_nodes=1, max_nodes=1
        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
        8. Check error message
        9. Execute scaleNodesDown action
        10. Check error message
        11. Execute scaleGatewaysUp action
        12. Check error message

Expected results:
       8. Error message like 'The maximum number of nodes has been reached' appears
      10. Error message like 'No nodes that can be removed' appears
      12. Error message like 'The maximum number of gateway nodes has been reached' appears

Actual result:
      8., 10., 12. There is no any error message
In horison Deployment Logs appears message like:
2016-04-04 12:38:22 — Action scaleNodesUp is scheduled
2016-04-04 12:38:27 — Deployment finished

Reproducibility:
always

Workaround:
 no

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"
  fuelmain_sha: "d605bcbabf315382d56d0ce8143458be67c53434"

Diagnostic Snapshot: https://drive.google.com/a/mirantis.com/file/d/0Bz15vbpS5ZPNYW9BX3REejhadEU/view?usp=sharing