chore(package): update @babel/core to version 7.6.4

Author: greenkeeper[bot]

package.json

@@ -97,7 +97,7 @@
   },
   "devDependencies": {
     "@babel/cli": "^7.6.4",
-    "@babel/core": "^7.4.3",
+    "@babel/core": "^7.6.4",
     "@babel/preset-env": "^7.4.3",
     "ascjs": "^3.0.0",
     "basichtml": "^1.1.1",