Update babel7 to the latest version 🚀 (#523)

* chore(package): update @babel/core to version 7.5.5

* chore(package): update @babel/plugin-proposal-decorators to version 7.4.4

Author: greenkeeper[bot]

package.json

@@ -126,8 +126,8 @@
     "uuid": "^3.3.2"
   },
   "devDependencies": {
-    "@babel/core": "7.2.2",
-    "@babel/plugin-proposal-decorators": "^7.1.0",
+    "@babel/core": "7.5.5",
+    "@babel/plugin-proposal-decorators": "^7.4.4",
     "@commitlint/cli": "^7.0.0",
     "@commitlint/config-conventional": "^8.0.0",
     "@groupher/eslint-config-web": "1.1.1",