outputting to file called output.txt. This is not a CSV like we will probably want the simulation to make, but I am not sure what format we need to follow so I am using this for now so the basic output can be displayed. Output is appended to the end of a file, so output will be there for every simulation run
added tests to see if the objects are created properly, but we still need to have more tests and think about how to deal with errors, improper input, etc
file output is included - need more tests and general cleanup