Remove dependency changes

package.json

@@ -31,7 +31,7 @@
     "webpack-prod": "NODE_OPTIONS=\"--max-old-space-size=3584\" NODE_ENV=production webpack --config config/webpack.config.js"
   },
   "dependencies": {
-    "@babel/core": "^7.8.4",
+    "@babel/core": "^7.6.2",
     "@babel/plugin-proposal-class-properties": "^7.5.5",
     "@babel/plugin-proposal-json-strings": "^7.2.0",
     "@babel/plugin-proposal-optional-chaining": "^7.7.5",
@@ -65,7 +65,7 @@
     "codesandbox-api": "^0.0.20",
     "compression-webpack-plugin": "^3.0.1",
     "copy-webpack-plugin": "^5.0.5",
-    "core-js": "^3.6.4",
+    "core-js": "^3.2.1",
     "cropper": "^2.3.0",
     "css-loader": "^1.0.0",
     "d3": "^4.13.0",
@@ -210,4 +210,4 @@
     "node": ">=8.10.0",
     "yarn": "^1.10.0"
   }
-}
\ No newline at end of file
+}