Updated yarn ship script

no issue

- Updates `yarn script` to use same consistent format we use across org
- Removes use of `npm` in publish
- Adds `preship` to run lint - ideally should run tests but react tests run in interactive mode and are very slow atm, need to sort that out first.

ghost/portal/package.json

@@ -31,7 +31,8 @@
     "test": "react-scripts test",
     "eject": "react-scripts eject",
     "lint": "eslint src --ext .js --cache",
-    "ship": "npm publish",
+    "preship": "yarn lint",
+    "ship": "STATUS=$(git status --porcelain); echo $STATUS; if [ -z \"$STATUS\" ]; then yarn publish && git push ${GHOST_UPSTREAM:-upstream} master --follow-tags; fi",
     "posttest": "yarn lint",
     "prepublishOnly": "yarn build"
   },