Rewrote ships#<<. #each algorithm to check if the target coordinates were already occupied did not behaved as intended. wrote #valid_ship_placement? method to carry out original intention. Tested; appears to fix problems.

Refactoring ShipsGenerator along with rewrite of ManualShipsGenerator.
Finished refactoring of ManualShipGenerator. Now functions. Does not allow for placement of two ships on same coords.
Renamed manual_ship_gen.rb to manual_ship_generator.rb, revised requires
Merge pull request #1 from bneuman619/BEN/refactor_manual_ship_generator

Ben/refactor manual ship generator