Added test script and update dependencies

package.json

@@ -4,6 +4,7 @@
   "description": "Modern URL shortener.",
   "main": "./server/server.js",
   "scripts": {
+    "test": "mocha --require babel-core/register './client/**/__test__/*.js'",
     "dev": "node ./server/server.js",
     "build": "next build ./client",
     "start": "NODE_ENV=production node ./server/server.js",
@@ -71,9 +72,13 @@
     "useragent": "^2.2.1"
   },
   "devDependencies": {
+    "babel": "^6.23.0",
     "babel-cli": "^6.26.0",
+    "babel-core": "^6.26.3",
     "babel-eslint": "^8.0.2",
     "babel-plugin-styled-components": "^1.3.0",
+    "chai": "^4.1.2",
+    "deep-freeze": "^0.0.1",
     "eslint": "^4.12.0",
     "eslint-config-airbnb": "^16.1.0",
     "eslint-config-prettier": "^2.9.0",
@@ -82,6 +87,7 @@
     "eslint-plugin-prettier": "^2.6.0",
     "eslint-plugin-react": "^7.5.1",
     "husky": "^0.15.0-rc.6",
+    "mocha": "^5.2.0",
     "prettier": "^1.10.2"
   }
 }