butterflow 0.1.4 (new formula)

A tool that lets you make slow motion and smooth motion videos from
the command line.

butterflow: fix depends, new setup_install method

* Removed redundant `depends_on python, numpy` since opencv already
  has them as dependencies
* Replaced `python setup.py install` with
  `Language::Python.setup_install`

butterflow: changed module linking locations

Don't link modules to Homebrew site-packages.