include flow check in npm test

package.json

@@ -15,7 +15,7 @@
     "dev": "webpack --watch --config build/webpack.dist.dev.config.js",
     "dev:test": "karma start build/karma.dev.config.js",
     "dev:ssr": "webpack --watch --config build/webpack.ssr.dev.config.js",
-    "test": "npm run lint && npm run test:unit && npm run test:e2e && npm run test:ssr",
+    "test": "npm run lint && flow check && npm run test:unit && npm run test:e2e && npm run test:ssr",
     "build": "NODE_ENV=production node build/build.js",
     "lint": "eslint src build test",
     "test:unit": "NODE_ENV=development karma start build/karma.unit.config.js",