[stats] Plugin information is incorrectly exported into csv file

[Andrey Sledzinskiy]

{

    "build_id": "2015-03-11_22-54-44",
    "ostf_sha": "ecb8e294b0acbdc5b0300d5e39028fb26ecc9088",
    "build_number": "188",
    "release_versions":

{

    "2014.2-6.1":

{

    "VERSION":

{

    "build_id": "2015-03-11_22-54-44",
    "ostf_sha": "ecb8e294b0acbdc5b0300d5e39028fb26ecc9088",
    "build_number": "188",
    "api": "1.0",
    "nailgun_sha": "a720a2da99690eb2d2c19ddc5d739384312a8ac2",
    "production": "docker",
    "python-fuelclient_sha": "0f4ca9c2798da34797dd082130d22cac04c998a9",
    "astute_sha": "5cdd4ae4037aa29f4c876d441af15cad82f5a6cb",
    "feature_groups":

            [
                "mirantis"
            ],
            "release": "6.1",
            "fuelmain_sha": "0791400dd8224647ff9a5cb8051ce82b2c8863b1",
            "fuellib_sha": "e660cbdfc506197e7f79a4bf7caab2990953abe3"
        }
    }

},
"auth_required": true,
"api": "1.0",
"nailgun_sha": "a720a2da99690eb2d2c19ddc5d739384312a8ac2",
"production": "docker",
"python-fuelclient_sha": "0f4ca9c2798da34797dd082130d22cac04c998a9",
"astute_sha": "5cdd4ae4037aa29f4c876d441af15cad82f5a6cb",
"feature_groups":

    [
        "mirantis"
    ],
    "release": "6.1",
    "fuelmain_sha": "0791400dd8224647ff9a5cb8051ce82b2c8863b1",
    "fuellib_sha": "e660cbdfc506197e7f79a4bf7caab2990953abe3"

}

Steps:
1. Install fuel and create any cluster with any selected plugin
2. Send stat to collector
3. Export /api/v1/csv/clusters

Expected - info about plugins isn't empty for cluster
Actual - info is empty

db dump is attached

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/164123

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/164123
Committed: https://git.openstack.org/cgit/stackforge/fuel-stats/commit/?id=5ec8e18c660bbc9174ecce0e7920ad48f7706411
Submitter: Jenkins
Branch: master

commit 5ec8e18c660bbc9174ecce0e7920ad48f7706411
Author: Alexander Kislitsky <email address hidden>
Date: Fri Mar 13 12:32:11 2015 +0300

    Plugins info report added

    Plugins info can't be added into clusters report due to
    plugins are stored as list in the cluster, so additional
    report is required.
    Plugins report is available by url: /api/v1/csv/plugins

    Change-Id: Ia19d4578cb836438573dd1a494b54d1772f61b5d
    Closes-Bug: #1431362