Updated to latest Piston

Closes https://github.com/PistonDevelopers/piston-workspace/issues/118
Closes https://github.com/PistonDevelopers/piston-workspace/issues/117
Closes https://github.com/PistonDevelopers/piston-workspace/issues/116
Merge pull request #119 from bvssvni/master

Updated to latest Piston