test - unit - fail if tests contain a .only call

package-lock.json

@@ -7134,6 +7134,12 @@
         "domelementtype": "1.3.0"
       }
     },
+    "dot-only-hunter": {
+      "version": "1.0.3",
+      "resolved": "https://registry.npmjs.org/dot-only-hunter/-/dot-only-hunter-1.0.3.tgz",
+      "integrity": "sha1-9k0h7b5v8xFJlfEGGmGpNcMAIEs=",
+      "dev": true
+    },
     "dotenv": {
       "version": "5.0.1",
       "resolved": "https://registry.npmjs.org/dotenv/-/dotenv-5.0.1.tgz",

package.json

@@ -9,7 +9,7 @@
     "dist": "gulp dist",
     "doc": "jsdoc -c development/tools/.jsdoc.json",
     "test": "npm run test:unit && npm run test:integration && npm run lint",
-    "test:unit": "cross-env METAMASK_ENV=test mocha --exit --require test/setup.js --recursive \"test/unit/**/*.js\"",
+    "test:unit": "cross-env METAMASK_ENV=test mocha --exit --require test/setup.js --recursive \"test/unit/**/*.js\" && dot-only-hunter",
     "test:single": "cross-env METAMASK_ENV=test mocha --require test/helper.js",
     "test:integration": "npm run test:integration:build && npm run test:flat && npm run test:mascara",
     "test:integration:build": "gulp build:scss",
@@ -219,6 +219,7 @@
     "css-loader": "^0.28.11",
     "deep-freeze-strict": "^1.1.1",
     "del": "^3.0.0",
+    "dot-only-hunter": "^1.0.3",
     "envify": "^4.0.0",
     "enzyme": "^3.3.0",
     "enzyme-adapter-react-15": "^1.0.5",