upgrades core to 8.4.2

core/package.json

@@ -5,19 +5,50 @@
   "private": true,
   "scripts": {
     "build:js": "node ./scripts/js/babel-es6-build.js",
+    "build:js-dev": "cross-env NODE_ENV=development node ./scripts/js/babel-es6-build.js",
     "watch:js": "node ./scripts/js/babel-es6-watch.js",
-    "lint:js": "eslint . || exit 0"
+    "watch:js-dev": "cross-env NODE_ENV=development node ./scripts/js/babel-es6-watch.js",
+    "lint:core-js": "node ./node_modules/eslint/bin/eslint.js --ext=.es6.js . || exit 0",
+    "lint:css": "stylelint \"**/*.css\" || exit 0",
+    "lint:css-checkstyle": "stylelint \"**/*.css\" --custom-formatter ./node_modules/stylelint-checkstyle-formatter/index.js || exit 0"
   },
   "devDependencies": {
-    "babel-core": "6.17.0",
-    "babel-preset-es2015": "6.16.0",
-    "chokidar": "1.6.0",
-    "eslint": "3.8.1",
-    "glob": "^7.1.1"
+    "babel-core": "6.24.1",
+    "babel-plugin-add-header-comment": "1.0.3",
+    "babel-preset-env": "1.4.0",
+    "chalk": "^1.1.3",
+    "chokidar": "1.6.1",
+    "cross-env": "^4.0.0",
+    "eslint": "3.19.0",
+    "eslint-config-airbnb": "14.1.0",
+    "eslint-plugin-import": "2.2.0",
+    "eslint-plugin-jsx-a11y": "4.0.0",
+    "eslint-plugin-react": "6.10.3",
+    "glob": "7.1.1",
+    "minimist": "^1.2.0",
+    "stylelint": "^7.10.1",
+    "stylelint-checkstyle-formatter": "^0.1.0",
+    "stylelint-config-standard": "^16.0.0",
+    "stylelint-no-browser-hacks": "^1.0.2"
   },
   "babel": {
     "presets": [
-      "es2015"
+      [
+        "env",
+        {
+          "modules": false,
+          "targets": {
+            "browsers": [
+              "ie >= 9",
+              "edge >= 13",
+              "firefox >= 5",
+              "opera >= 12",
+              "safari >= 5",
+              "chrome >= 56"
+            ]
+          }
+        }
+      ]
     ]
   }
 }