Bump websocket-extensions from 0.1.3 to 0.1.5 (#529)

Bumps [websocket-extensions](https://github.com/faye/websocket-extensions-ruby) from 0.1.3 to 0.1.5.
- [Release notes](https://github.com/faye/websocket-extensions-ruby/releases)
- [Changelog](https://github.com/faye/websocket-extensions-ruby/blob/master/CHANGELOG.md)
- [Commits](https://github.com/faye/websocket-extensions-ruby/compare/0.1.3...0.1.5)

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Gemfile.lock

@@ -375,7 +375,7 @@ GEM
       hashdiff
     websocket-driver (0.7.0)
       websocket-extensions (>= 0.1.0)
-    websocket-extensions (0.1.3)
+    websocket-extensions (0.1.5)
     whenever (0.10.0)
       chronic (>= 0.6.3)
     will_paginate (3.1.6)