Added first come first served scheduling (#1722)
Added first come first served scheduling (#1722)

* Added FCFS

* Fixed spelling error

* Rename fcfs.py to first_come_first_served.py

* Fixed FCFS and added tests.

* Made changes requested

* Use enumerate() instead of range(len())

Co-authored-by: Christian Clauss <585dd401264c1e46d17ebec1862e5d2a9b6a6c5d@me.com>

TheAlgorithms/Python