Figlet no arguments test

[ZRexshima]

I added a test to check the error code of figlet.py run without arguments.

There was not a test for exit code when running figlet.py without arguments. This is a requirement for the assignment that should randomly select a font, prompt for input, then output the ASCII art.

This is a replacement of PR #275. This time it only has the individual change.

[bxngyn]

Thanks for submitting a PR!

In test_no_arguments, the if condition and the raise statement are mismatched. Also, I believe that since the program is waiting for the user's input, we should use prompt=True. Essentially, if figlet.py is ran without any args and a valid std input (expected behavior), then we would expect a successful exit code of 0, but the raise statement doesn't match this expectation.

[rongxin-liu]

Echoing @bxngyn, I think we can simply test whether running the program without interacting with it returns an exit code of 0. If it does, then the program fails the no arguments test, because it should exit with a non-zero code when no arguments are provided.

[ZRexshima]

I changed the prompt argument to True and changed the messaging for clarity.

[rongxin-liu]

Thank you!