Bite 7. Parsing dates from logs

In this Bite we will look at this short server log, finding the first and last system shutdown events:

INFO 2014-07-03T23:27:51 supybot Shutdown initiated.
...
INFO 2014-07-03T23:31:22 supybot Shutdown initiated.

You'll need to calculate the time between these two events. First extract the timestamps from the log entries and convert them to datetime objects. Then use datetime.timedelta to calculate the time difference between them.

You can assume the log is sorted in ascending order. Check out each function's docstring and the TESTS for more details on how to solve this Bite.

Good luck, keep calm, and code in Python!