chore(tools): remove gulp in favour of cross-env

package.json

@@ -19,15 +19,16 @@
     "commitmsg": "commitlint -e",
     "deploy-dev": "serverless --stage=dev deploy",
     "deploy-prod": "serverless --stage=prod deploy",
-    "format": "prettier --write es5 './**/*.js' && yarn lint",
+    "format": "prettier --write es5 './**/*.{js,json}' && yarn lint",
     "lint": "eslint ./**/*.js --fix",
     "prepare-production": "snyk protect",
     "prepublish": "yarn snyk-protect",
     "snyk-protect": "snyk protect",
     "snyk-test": "snyk test",
-    "start": "gulp",
-    "test": "JWT_CERT=test jest --runInBand",
-    "test-ci": "JWT_CERT=test node_modules/.bin/jest --runInBand"
+    "start":
+      "cross-env DEBUG=fcc:* nodemon node_modules/serverless/bin/serverless offline start --skipCacheInvalidation",
+    "test": "cross-env JWT_CERT=test jest",
+    "test-ci": "cross-env JWT_CERT=test jest --runInBand"
   },
   "config": {
     "commitizen": {
@@ -68,14 +69,13 @@
     "@commitlint/travis-cli": "^6.1.3",
     "babel-plugin-transform-es2015-modules-commonjs": "^6.26.0",
     "commitizen": "^2.9.6",
+    "cross-env": "^5.1.4",
     "cz-customizable": "^5.2.0",
     "eslint": "^4.19.1",
     "eslint-config-freecodecamp": "^1.1.1",
     "eslint-plugin-import": "^2.11.0",
     "eslint-plugin-prefer-object-spread": "^1.2.1",
     "eslint-plugin-react": "^7.7.0",
-    "gulp": "^4.0.0",
-    "gulp-nodemon": "^2.2.1",
     "husky": "^0.14.3",
     "jest": "^22.4.3",
     "jest-cli": "^22.4.3",