Incorrectly formatted output for tests failing due to extra calls to input

[jhcole]

[jscarfo11]

After debugging, this is due to the way our format error function works when using the test.failure exception attribute. When using this, it takes the str of the error message that is set as the error message and passes the values to the init of that error message. Leaving this as a note for help refactoring the errors after #86 is merged.