updating release scripts for 4.x

package.json

@@ -15,14 +15,12 @@
   "scripts": {
     "preversion": "npm test && npm run build",
     "version": "git commit -am \"Update dist for release\" && git checkout -b release && git add -f dist/",
-    "postversion": "git push --tags && git checkout master && git branch -D release && git push",
+    "postpublish": "git push --tags && git checkout - && git branch -D release && git push",
     "testee": "testee test/test.html --browsers firefox",
     "test": "npm run detect-cycle && npm run jshint && npm run testee",
     "jshint": "jshint ./*.js --config",
-    "release:pre": "npm version prerelease && npm publish --tags=pre",
     "release:patch": "npm version patch && npm publish",
     "release:minor": "npm version minor && npm publish",
-    "release:major": "npm version major && npm publish",
     "build": "node build.js",
     "detect-cycle": "detect-cyclic-packages --ignore done-serve"
   },