Use ciso8601 to parse CSV dates, fixes #443

[peterbe]

No description provided.

[peterbe]

In my virtualenv:

Python 3.6.5 (default, Mar 30 2018, 06:41:53)
[GCC 4.2.1 Compatible Apple LLVM 9.0.0 (clang-900.0.39.2)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import ciso8601
>>> ciso8601.parse_datetime('2017-06-11T12:20:10.2Z')
datetime.datetime(2017, 6, 11, 12, 20, 10, 200000, tzinfo=<UTC>)

On the Docker instance in CI:

Python 3.6.5 (default, Mar 31 2018, 01:18:39)
[GCC 4.9.2] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import ciso8601
>>> ciso8601.parse_datetime('2017-06-11T12:20:10.2Z')
datetime.datetime(2017, 6, 11, 12, 20, 10, 200000)

Awesome. I guess I need to read the docs a bit better or write a wrapper function that makes this more predictably across different environments.

[peterbe]

The reason is because I had pytz installed in my virtualenv. It's not in requirements.txt so I must have installed it from some other dev tool.

See closeio/ciso8601#19