read_json tz handling when it's just a list
http://stackoverflow.com/questions/22995828/json-extension-file-timestamp-pandas-python

Perhaps two parts here, first date is not converted unless col is passed in this example. Also tz is lost (I thought it should be 0 somewhere e.g. utcoffset).

```
js = '["2012-03-01T00:05:55+00:00", "2012-03-01T00:06:23+00:00", "2012-03-01T00:06:52+00:00", "2012-03-01T00:11:23+00:00", "2012-03-01T00:12:47+00:00", "2012-03-01T00:12:54+00:00", "2012-03-01T00:16:14+00:00", "2012-03-01T00:17:31+00:00", "2012-03-01T00:21:23+00:00", "2012-03-01T00:21:26+00:00", "2012-03-01T00:22:25+00:00", "2012-03-01T00:28:24+00:00", "2012-03-01T00:31:21+00:00", "2012-03-01T00:32:20+00:00", "2012-03-01T00:33:32+00:00", "2012-03-01T00:35:21+00:00", "2012-03-01T00:38:14+00:00", "2012-03-01T00:39:24+00:00", "2012-03-01T00:43:12+00:00", "2012-03-01T00:46:13+00:00", "2012-03-01T00:46:31+00:00", "2012-03-01T00:48:03+00:00", "2012-03-01T00:49:34+00:00", "2012-03-01T00:49:54+00:00", "2012-03-01T00:55:19+00:00", "2012-03-01T00:56:27+00:00", "2012-03-01T00:56:32+00:00"]'

In [44]: pd.read_json(js).head(2)  # strings !
Out[44]:
                           0
0  2012-03-01T00:05:55+00:00
1  2012-03-01T00:06:23+00:00

In [45]: pd.read_json(js, convert_dates=[0]).head(2)
Out[45]:
                    0
0 2012-03-01 00:05:55
1 2012-03-01 00:06:23

In [46]: pd.read_json(js, convert_dates=[0]).iloc[0, 0]
Out[46]: Timestamp('2012-03-01 00:05:55', tz=None)
```
