title: Treepoem barcode generator unable to find ghostscript
body: <p>I'm trying to generate a pdf417 barcode in python using treepoem but pycharm keeps giving me the following error:</p>
  
  <p>Traceback (most recent call last):</p>
  
  <p>File "C:/Users/./Documents/barcodes.py", line 175, in 
      image = generate_barcode(barcode_type="pdf417",data=barcode, options=dict(eclevel=5, rows=27, columns=12))
    File "C:\Users.\AppData\Local\Programs\Python\Python36-32\lib\site-packages\treepoem__init__.py", line 141, in generate_barcode
      bbox_lines = _get_bbox(code)
    File "C:\Users.\AppData\Local\Programs\Python\Python36-32\lib\site-packages\treepoem__init__.py", line 81, in _get_bbox
      ghostscript = _get_ghostscript_binary()
    File "C:\Users.\AppData\Local\Programs\Python\Python36-32\lib\site-packages\treepoem__init__.py", line 108, in _get_ghostscript_binary
      'Cannot determine path to ghostscript, is it installed?'
  treepoem.TreepoemError: Cannot determine path to ghostscript, is it installed?</p>
  
  <p>I've tried to install ghostcript, using both the .exe I found online and using pip install ghostscript (successfully completed the first time, and now tells me the requirement is satisfied), yet I still keep getting this error. Any ideas on how to fix it?</p>