Bump tinymce from 5.2.2 to 5.4.1

Bumps [tinymce](https://github.com/tinymce/tinymce-dist) from 5.2.2 to 5.4.1.
- [Release notes](https://github.com/tinymce/tinymce-dist/releases)
- [Changelog](https://github.com/tinymce/tinymce-dist/blob/master/changelog.txt)
- [Commits](https://github.com/tinymce/tinymce-dist/compare/5.2.2...5.4.1)

Signed-off-by: dependabot[bot] <support@github.com>

package.json

@@ -72,7 +72,7 @@
     "redux": "^3.7.2",
     "setimmediate": "1.0.5",
     "sortablejs": "1.10.0",
-    "tinymce": "5.2.2",
+    "tinymce": "5.4.1",
     "tslib": "^1.10.0",
     "uncontrollable": "7.0.2",
     "video-react": "0.9.4"