Add n numbers

Problem Description

The goal of this exercise is to write a function that adds all of the numbers up to a given number.

Example 1

Value of n: 4
>>> 10      # 1 + 2 + 3 + 4 = 10

Example 2

Value of n: 3
>>> 6       # 1 + 2 + 3 = 6

Suggested Approach

1. Use a loop that repeats n times
2. Use a counter and add its value to the total each time
3. return the total
4. Test your function with the print statement provided
5. If desired, modify the code in 'main' to allow the user to input a number.
6. Test with pytest