Bump websocket-extensions from 0.1.2 to 0.1.5 (#8)

Author: dependabot[bot]

Gemfile.lock

@@ -114,7 +114,7 @@ GEM
       hashdiff
     websocket-driver (0.6.5)
       websocket-extensions (>= 0.1.0)
-    websocket-extensions (0.1.2)
+    websocket-extensions (0.1.5)
     whenever (0.9.7)
       chronic (>= 0.6.3)