🛠 Use yarn & git directly for yarn ship

- np causes too many problems, this is much simpler
- use preship to build and run tests before attempting to ship
- if build causes files to need committing, git status porcelain will flag this

Author: ErisDS

Diff for: package.json

@@ -8,7 +8,8 @@
     "lint": "eslint lib test/*_spec.js",
     "test": "yarn build && yarn lint && NODE_ENV=testing mocha -- $(find test -name '*_spec.js')",
     "coverage": "NODE_ENV=testing istanbul cover --dir test/coverage _mocha -- $(find test -name '*._spec.js')",
-    "ship": "np"
+    "preship": "yarn test",
+    "ship": "STATUS=$(git status --porcelain); echo $STATUS; if [ -z \"$STATUS\" ]; then yarn publish && git push --follow-tags; fi"
   },
   "author": "Ghost Foundation",
   "homepage": "http://ghost.org",
@@ -35,7 +36,6 @@
     "jison": "0.4.18",
     "knex": "0.8.6",
     "mocha": "4.0.1",
-    "np": "2.19.0",
     "should": "13.1.0",
     "sinon": "4.0.1"
   }