Remove old bump task and deps

We do not use the 'bump' task anymore and semver had a reported vulnerability. Clean up

Author: vladikoff

internal-tasks/bump.js

@@ -60,8 +60,6 @@
     "grunt-contrib-nodeunit": "~1.0.0",
     "grunt-contrib-watch": "~1.0.0",
     "grunt-eslint": "~18.1.0",
-    "semver": "5.3.0",
-    "shelljs": "~0.7.8",
     "temporary": "~0.0.4",
     "through2": "~2.0.0"
   },