Investigate using AFL to generate SEG-Y files for testing

[rob-smallshire]

It could be interesting to used the American Fuzzy Lop fuzzer to generate SEG-Y inputs to Segpy to ensure that our error handling is in good shape in the case of malformed input. Which is to say, Segpy should always fail with a predictable, documented exception.

Here's an article on using AFL with Python: https://alexgaynor.net/2015/apr/13/introduction-to-fuzzing-in-python-with-afl/