add --exit option to mocha

Author: ryanbrainard

package.json

@@ -9,7 +9,7 @@
     "clean": "rimraf lib dist coverage",
     "lint": "eslint src test",
     "prepublish": "npm run clean && npm run lint && npm run build",
-    "test": "mocha --require babel-core/register --recursive --require ./test/setup.js",
+    "test": "mocha --require babel-core/register --recursive --require ./test/setup.js --exit",
     "test:watch": "npm test -- --watch",
     "test:cov": "babel-node ./node_modules/isparta/bin/isparta cover ./node_modules/mocha/bin/_mocha -- --recursive --require ./test/setup.js"
   },