Missing requirement for bitarray

[rleigh-codelibre]

setup.py does not currently have this as a requirement in install_requires, so the dependency is not pulled in:

Traceback (most recent call last):
  File "dump_planes.py", line 15, in <module>
    from libtiff import TIFF
  File "/tmp/ve/lib/python3.7/site-packages/pylibtiff-0.4.4.dev0+ad644a2-py3.7-linux-x86_64.egg/libtiff/__init__.py", line 35, in <module>
    import bitarray as _bitarray    # noqa: F402
ModuleNotFoundError: No module named 'bitarray'