Create vtk6.rb from https://github.com/Homebrew/homebrew-science/blob/092849afd643314eda1699ab6e6f1a793df91521/vtk.rb
Create vtk6.rb from https://github.com/Homebrew/homebrew-science/blob/092849afd643314eda1699ab6e6f1a793df91521/vtk.rb

ahundt/homebrew-science