Fix time format error

[ghost]

Fixes issue #1

  File "./cdn_report.py", line 234, in <module>
    secs_create = datetime.strptime(ckey["created"], '%Y-%m-%dt%H:%M:%S.000+0000').strftime("%s")
  File "/usr/lib64/python3.6/_strptime.py", line 565, in _strptime_datetime
    tt, fraction = _strptime(data_string, format)
  File "/usr/lib64/python3.6/_strptime.py", line 362, in _strptime
    (data_string, format))
ValueError: time data '2016-01-25t20:53:06+0000' does not match format '%Y-%m-%dt%H:%M:%S.000+0000'