Upgrade babel to 7.4.4

Signed-off-by: Takuya Noguchi <takninnovationresearch@gmail.com>

changelogs/unreleased/update-babel-to-7-4-4.yml

+---
+title: Upgrade babel to 7.4.4
+merge_request: 28437
+author: Takuya Noguchi
+type: other

package.json

@@ -28,13 +28,13 @@
     "webpack-prod": "NODE_OPTIONS=\"--max-old-space-size=3584\" NODE_ENV=production webpack --config config/webpack.config.js"
   },
   "dependencies": {
-    "@babel/core": "^7.2.2",
-    "@babel/plugin-proposal-class-properties": "^7.3.0",
+    "@babel/core": "^7.4.4",
+    "@babel/plugin-proposal-class-properties": "^7.4.4",
     "@babel/plugin-proposal-json-strings": "^7.2.0",
-    "@babel/plugin-proposal-private-methods": "^7.3.0",
+    "@babel/plugin-proposal-private-methods": "^7.4.4",
     "@babel/plugin-syntax-dynamic-import": "^7.2.0",
     "@babel/plugin-syntax-import-meta": "^7.2.0",
-    "@babel/preset-env": "^7.3.1",
+    "@babel/preset-env": "^7.4.4",
     "@gitlab/csslab": "^1.9.0",
     "@gitlab/svgs": "^1.60.0",
     "@gitlab/ui": "^3.10.0",