Building PiCrate gem on Linux
Requirements:-
- 
    Latest jogl-2.4.0-rc jars (place in ~/jogl-2.4-rc2021011 folder see jogl-jars). 
- 
    jdk-11+ and maven 
Simply clone this distribution, then rake to build and test gem
git clone --depth 1 https://github.com/ruby-processing/PiCrate.git
cd PiCrate
rake # to build gem