add browser test target

example.js

@@ -18,3 +18,5 @@ var plainText = new Buffer(cipher.length - sodium.crypto_secretbox_MACBYTES)
 sodium.crypto_secretbox_open_easy(plainText, cipher, nonce, key)
 
 console.log('Plaintext:', plainText.toString())
+
+if (typeof window !== 'undefined') window.close()

package.json

@@ -6,7 +6,13 @@
   "dependencies": {
     "blakejs": "^1.0.1"
   },
-  "devDependencies": {},
+  "devDependencies": {
+    "browser-run": "^4.0.2",
+    "browserify": "^14.1.0"
+  },
+  "scripts": {
+    "browser": "browserify example.js | browser-run"
+  },
   "repository": {
     "type": "git",
     "url": "https://github.com/mafintosh/sodium-javascript.git"