Add preversion/postversion scripts.

Allows releasing with simple `npm version` invocation.

Author: rwjblue

package.json

@@ -7,7 +7,9 @@
     "ember-module-migrator": "./bin/ember-module-migrator"
   },
   "scripts": {
-    "test": "mocha test/**/*-test.js"
+    "test": "mocha test/**/*-test.js",
+    "preversion": "npm test",
+    "postversion": "git push && git push --tags"
   },
   "author": "Robert Jackson <[email protected]>",
   "license": "MIT",