Fix OS X code signing issue on Travis CI (https://github.com/electron-userland/electron-builder/issues/398)
Fix OS X code signing issue on Travis CI (https://github.com/electron-userland/electron-builder/issues/398)

cheton/piduino-grbl,cheton/cnc,cheton/cnc.js,cheton/cnc.js,cheton/piduino-grbl,cheton/cnc.js,cheton/cnc,cheton/cnc,cncjs/cncjs,cncjs/cncjs,cheton/piduino-grbl,cncjs/cncjs