Adds 'gen core' to generate all the core (RubotoActivity, RubotoService, etc.) classes; now generates core classes during 'gen app'; removes requirement to target android-8; removes 'update-jruby' and adds 'update jruby' and 'update ruboto'; fixes some bugs in java class generation
Adds 'gen core' to generate all the core (RubotoActivity, RubotoService, etc.) classes; now generates core classes during 'gen app'; removes requirement to target android-8; removes 'update-jruby' and adds 'update jruby' and 'update ruboto'; fixes some bugs in java class generation

lucasallan/ruboto,Jodell88/ruboto,ruboto/ruboto,Jodell88/ruboto,lucasallan/ruboto,Jodell88/ruboto,lucasallan/ruboto,ruboto/ruboto,baberthal/ruboto,ruboto/ruboto,baberthal/ruboto,baberthal/ruboto