Bump tinymce from 5.6.0 to 5.7.1

Bumps [tinymce](https://github.com/tinymce/tinymce-dist) from 5.6.0 to 5.7.1.
- [Release notes](https://github.com/tinymce/tinymce-dist/releases)
- [Changelog](https://github.com/tinymce/tinymce-dist/blob/master/CHANGELOG.md)
- [Commits](tinymce/tinymce-dist@5.6.0...5.7.1)

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

Author: dependabot[bot]

package-lock.json

@@ -73,7 +73,7 @@
     "rxjs-compat": "6.3.0",
     "socicon": "3.0.5",
     "style-loader": "^1.1.3",
-    "tinymce": "4.9.11",
+    "tinymce": "5.7.1",
     "tslib": "^2.0.0",
     "typeface-exo": "0.0.22",
     "web-animations-js": "^2.3.2",