chore(package): update @babel/plugin-external-helpers to version 7.10.1

Closes #17

Author: greenkeeper[bot]

package.json

@@ -48,7 +48,7 @@
   "devDependencies": {
     "@babel/core": "7.10.2",
     "@babel/helper-module-imports": "7.10.1",
-    "@babel/plugin-external-helpers": "7.2.0",
+    "@babel/plugin-external-helpers": "7.10.1",
     "@babel/plugin-transform-object-assign": "7.2.0",
     "@babel/preset-env": "7.5.5",
     "@mediagoom/devman": "0.0.12",