Bump elm/core from 1.0.4 to 1.0.5 in /playground/viewer-elm

Bumps [elm/core](https://github.com/elm/core) from 1.0.4 to 1.0.5.
- [Release notes](https://github.com/elm/core/releases)
- [Changelog](https://github.com/elm/core/blob/master/changelog.md)
- [Commits](https://github.com/elm/core/compare/1.0.4...1.0.5)

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

playground/viewer-elm/elm.json

@@ -8,7 +8,7 @@
         "direct": {
             "bburdette/websocket": "1.0.3",
             "elm/browser": "1.0.2",
-            "elm/core": "1.0.4",
+            "elm/core": "1.0.5",
             "elm/html": "1.0.0",
             "elm/json": "1.1.3",
             "elm/time": "1.0.0",