ENH: Implement bubble sort

[seberg]

We currently have a small implementation of a merge sort algorithm only. We would like to also provide a bubble_sort implementation.

For information on bubble sort, please see: https://en.wikipedia.org/wiki/Bubble_sort

Working on this issue

Implementing bubblesort consists of the following things:

• Find the existing bubble_sort stub and replace it with your implementation.
• Add documentation (you can look at merge_sort for inspiration).
• Add some tests by expanding test_bubble_sort in test_sorting.py.

Once you have made your changes, and committed them to a new branch, you can create a PR!

[andrea-petrocchi]

I'm on it.

[Nikoleta-v3]

I am closing this. It was addressed by #30 and #31