source: Codewars
Given a 2D (nested) list of size m * n, find the sum of the minimum values in
each row.
Note: You will always be given a non-empty list containing positive values.
[
[1, 2, 3, 4, 5], # minimum value of row is 1
[5, 6, 7, 8, 9], # minimum value of row is 5
[20, 21, 34, 56, 100] # minimum value of row is 20
]The function should return 26 because the sum of the minimums is
1 + 5 + 20 = 26.