fix(package): update commander to version 3.0.2

Closes #21

Author: greenkeeper[bot]

package.json

@@ -24,7 +24,7 @@
   "license": "MIT",
   "dependencies": {
     "chalk": "^1.1.3",
-    "commander": "^2.9.0",
+    "commander": "^3.0.2",
     "fs-extra": "^4.0.0",
     "image-type": "^3.0.0",
     "read-chunk": "^2.0.0",