Bump scout_apm from 5.3.1 to 5.3.5

Bumps [scout_apm](https://github.com/scoutapp/scout_apm_ruby) from 5.3.1 to 5.3.5.
- [Changelog](https://github.com/scoutapp/scout_apm_ruby/blob/master/CHANGELOG.markdown)
- [Commits](scoutapp/scout_apm_ruby@v5.3.1...v5.3.5)

---
updated-dependencies:
- dependency-name: scout_apm
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Gemfile.lock

@@ -386,7 +386,7 @@ GEM
       sprockets (> 3.0)
       sprockets-rails
       tilt
-    scout_apm (5.3.1)
+    scout_apm (5.3.5)
       parser
     sentry-raven (2.13.0)
       faraday (>= 0.7.6, < 1.0)