[stats] Getting of all oswl reports into zip file failed with TypeError: sequence item 0: expected string, dict found

[Andrey Sledzinskiy]

Steps:
1. Try to get all oswl reports
curl -XGET http://localhost:8082/api/v1/csv/all > oswl.zip

Actual - it failed to zip all reports
Traceback (most recent call last):
  File "/home/asledzinskiy/Work/fuel-stats/venv/fuel-stats/local/lib/python2.7/site-packages/werkzeug/wsgi.py", line 693, in __next__
    return self._next()
  File "/home/asledzinskiy/Work/fuel-stats/venv/fuel-stats/local/lib/python2.7/site-packages/werkzeug/wrappers.py", line 81, in _iter_encoded
    for item in iterable:
  File "./fuel_analytics/api/resources/utils/export_utils.py", line 160, in flatten_data_as_csv
    for d in itertools.chain((names,), flatten_data):
  File "./fuel_analytics/api/resources/utils/oswl_stats_to_csv.py", line 86, in get_flatten_resources
    resource_keys_paths, {resource_type: resource})
  File "./fuel_analytics/api/resources/utils/export_utils.py", line 56, in get_flatten_data
    flatten_data.append(' '.join(d))
TypeError: sequence item 0: expected string, dict found
[pid: 2063|app: 0|req: 3/3] 127.0.0.1 () {24 vars in 291 bytes} [Mon Mar 23 11:06:51 2015] GET /api/v1/csv/volume => generated 513 bytes in 22 msecs (HTTP/1.1 200) 2 headers in 112 bytes (2 switches on core 0)
-------

dump of db is attached

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/167645
Committed: https://git.openstack.org/cgit/stackforge/fuel-stats/commit/?id=a6fb8e227247a0493d8a3eae6dd6c993f7b60021
Submitter: Jenkins
Branch: master

commit a6fb8e227247a0493d8a3eae6dd6c993f7b60021
Author: Alexander Kislitsky <email address hidden>
Date: Wed Mar 25 18:13:52 2015 +0300

    Fix for export attachments from volume

    Volume contains list of attachments. Export of attachments into CSV as enumerated fields implemented.
    Number of enumrations is added into config as CSV_VOLUME_ATTACHMENTS_NUM parameter.
    Enumeration of keys paths implemented in export_utils.
    Volume attachment skeleton added.

    Change-Id: I63eb2217c3564457a8ff4a5396eb7e7c40a76321
    Closes-Bug: #1434086
    Closes-Bug: #1435224