Follow-up issue to last - problems running on MacOS

[JustinGOSSES]

I don't get issue #1 anymore when I clone this repo. I do get it if I pip install it, so suspect the fix hasn't been pushed to package manager.

Now when I run from the cloned version I get the following behavior on MacOS:

When I run python3 vtk_reserves.py

I get error

Traceback (most recent call last):
  File "vtk_reserves.py", line 131, in <module>
    usage_gui(__doc__)
  File "/Users/justingosses/Code/junk/vtk_reserves/_gui.py", line 1231, in usage_gui
    AppTk(usage).mainloop()
  File "/Users/justingosses/Code/junk/vtk_reserves/_gui.py", line 2082, in __init__
    self.iconbitmap(default=self._iconfile)
  File "/Users/justingosses/anaconda/lib/python3.5/tkinter/__init__.py", line 1714, in wm_iconbitmap
    return self.tk.call('wm', 'iconbitmap', self._w, '-default', default)
_tkinter.TclError: wrong # args: should be "wm iconbitmap window ?bitmap?"```