You are given the length of a video in minutes. The format is mm:ss (e.g.: "02:54"). Create a function that takes the video length and return it in seconds.
minutes_to_seconds("01:00") ➞ 60
minutes_to_seconds("13:56") ➞ 836
minutes_to_seconds("10:60") ➞ False
False (see example #3)."121:49" is perfectly valid).