* Adding variable to fade out ambiguity
* More readability on merge sorting algorithm
* Updating merge_sort_fastest description and explaining why
* Adding tests file with imports
* Standardazing filenames and function names
* Adding test cases and test functions
* Adding test loop
* Putting 'user oriented code' inside main condition for having valid imports
* Fixing condition
* Updating tests: adding cases and todo list
* Refactoring first euler problem's first solution
