Squashed commit of the following:

commit b426ed0b3f0a174c0e0e2511f80b06e1bc957ee0
Author: Fremen DeRuvo <fremenderuvo@gmail.com>
Date:   Fri Sep 20 10:41:06 2013 -0500

    adds distance method
    [Closes #2]

commit 2bc6c40a7900783eb68de3f245b98d583ef9d55e
Author: Fremen DeRuvo <fremenderuvo@gmail.com>
Date:   Fri Sep 20 10:34:20 2013 -0500

    fixed math bug in trip duration

commit 3926230c8e18fe069323b857538103b5523aa746
Merge: 34ca10d 9ddd480
Author: Matt Buck <github@matthewbuck.com>
Date:   Fri Sep 20 10:30:04 2013 -0500

    Merge remote-tracking branch 'origin/master' into calculate-trip-time

    Conflicts:
    	train.rb

commit 34ca10d9f2fac432beb3388b75b3d8345c8498c0
Author: Matt Buck <github@matthewbuck.com>
Date:   Fri Sep 20 10:13:15 2013 -0500

    Add Train#calculate_trip_duration.