Design a Sum All Numbers Algorithm

In this lab, you will need to design a sum all numbers algorithm. **Objective:** Fulfill the user stories below and get all the tests to pass to complete the lab. **User Stories:** 1. You should have a function named `sumAll` that accepts an array of two numbers. 1. `sumAll([n, m])` should return the sum of `n` and `m` plus the sum of all the numbers between them. The lowest number will not always come first. For example, `sumAll([4,1])` should return `10` because sum of all the numbers between `1` and `4` (both inclusive) is `10`.