Add Up a Line

A fitness app saves each workout as one line of numbers: the minutes spent on each exercise, separated by commas.

Task: write line_total(line). It returns the total of all the numbers on the line, as a float.

• The line may end with "\n".
• Numbers can be whole or have a decimal point, and can be negative.
• A number may have spaces around it, like " 4 ".
• A blank line has a total of 0.0.