Stale input files in tests directory

[opotowsky]

cycamore/tests/input seems to contain some input files that are not used in testing. Instead, cycamore/input is the file path for the input files that are tested. Thanks to @abachma2 for figuring this out! Happy to PR this deletion but wanted to get feedback first (i.e., are the input files in tests/input used for something else?)

[abachma2]

After looking at tests/test_regression.py it looks like files from inputs/ and tests/inputs/ are being used in the testing suite. I think instead of removing the tests/input/ directory we should figure out why there are input files in two locations. Are the files in inputs/ used for things other than regression testing?

The tests/run_inputs.py looks for input files in the inputs/ directory, not tests/input. Is there a reason this happens?