ci(postpublish): removed the greenkeeper postpublish task that is no longer needed

Author: travi

package.json

@@ -21,7 +21,6 @@
     "preversion": "npm test",
     "commitmsg": "validate-commit-msg",
     "precommit": "npm test",
-    "postpublish": "greenkeeper-postpublish",
     "presemantic-release": "npm run build",
     "semantic-release": "semantic-release pre && npm publish && semantic-release post"
   },
@@ -64,7 +63,6 @@
     "good": "7.2.0",
     "good-console": "6.4.0",
     "good-squeeze": "5.0.2",
-    "greenkeeper-postpublish": "1.3.0",
     "hapi": "16.5.0",
     "hapi-mustache": "0.0.1",
     "husky": "0.14.3",