fix mascara build

package.json

@@ -9,7 +9,7 @@
     "ui": "npm run test:flat:build:states && beefy ui-dev.js:bundle.js --live --open --index=./development/index.html --cwd ./",
     "mock": "beefy mock-dev.js:bundle.js --live --open --index=./development/index.html --cwd ./",
     "watch": "mocha watch --recursive \"test/unit/**/*.js\"",
-    "mascara": "METAMASK_DEBUG=true node ./mascara/example/server",
+    "mascara": "gulp build && METAMASK_DEBUG=true node ./mascara/example/server",
     "dist": "npm run dist:clear && npm install && gulp dist",
     "dist:clear": "rm -rf node_modules/eth-contract-metadata && rm -rf node_modules/eth-phishing-detect",
     "test": "npm run lint && npm run test:coverage && npm run test:integration",