merge request 23 has broken install

@leo-singer Since merging !23 (merged), the unit tests fail with

Traceback (most recent call last):
  File "/home/kipp/local/bin/ligolw_print", line 4, in <module>
    __import__('pkg_resources').run_script('python-ligo-lw==1.7.0', 'ligolw_print')
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 665, in run_script
    self.require(requires)[0].run_script(script_name, ns)
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 1451, in run_script
    raise ResolutionError(
pkg_resources.ResolutionError: Script 'scripts/ligolw_print' not found in metadata at None

This does not correspond to line 4 of that script, but when I look inside $(which ligolw_print) it's nearly empty, and this error message does correspond to what is there. What happened to the programs in bin? Why are they empty, why does whatever python has done to them not work?