Bind release script to npm build script and add output to gitignore

Author: jackycute

.gitignore

@@ -7,3 +7,4 @@
 .idea
 *.iml
 /lib/codemirror.js
+codemirror.min.js

package.json

@@ -8,7 +8,7 @@
     "lib": "./lib"
   },
   "scripts": {
-    "build": "rollup -c",
+    "build": "rollup -c && ./release.sh",
     "watch": "rollup -w -c",
     "prepublish": "npm run-script build",
     "test": "node ./test/run.js",