Bump rack-attack from 6.3.0 to 6.3.1 (#8011)

Bumps [rack-attack](https://github.com/kickstarter/rack-attack) from 6.3.0 to 6.3.1.
- [Release notes](https://github.com/kickstarter/rack-attack/releases)
- [Changelog](https://github.com/kickstarter/rack-attack/blob/master/CHANGELOG.md)
- [Commits](https://github.com/kickstarter/rack-attack/compare/v6.3.0...v6.3.1)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Gemfile

@@ -72,7 +72,7 @@ gem "puma", "~> 4.3" # Puma is a simple, fast, threaded, and highly concurrent H
 gem "pundit", "~> 2.1" # Object oriented authorization for Rails applications
 gem "pusher", "~> 1.3" # Ruby library for Pusher Channels HTTP API
 gem "pusher-push-notifications", "~> 1.1" # Pusher Push Notifications Ruby server SDK
-gem "rack-attack", "~> 6.3.0" # Used to throttle requests to prevent brute force attacks
+gem "rack-attack", "~> 6.3.1" # Used to throttle requests to prevent brute force attacks
 gem "rack-cors", "~> 1.1" # Middleware that will make Rack-based apps CORS compatible
 gem "rack-timeout", "~> 0.6" # Rack middleware which aborts requests that have been running for longer than a specified timeout
 gem "rails", "~> 5.2" # Ruby on Rails

Gemfile.lock

@@ -544,7 +544,7 @@ GEM
       rest-client (~> 2.0, >= 2.0.2)
     pusher-signature (0.1.8)
     rack (2.2.2)
-    rack-attack (6.3.0)
+    rack-attack (6.3.1)
       rack (>= 1.0, < 3)
     rack-cors (1.1.1)
       rack (>= 2.0.0)
@@ -929,7 +929,7 @@ DEPENDENCIES
   pundit-matchers (~> 1.6)
   pusher (~> 1.3)
   pusher-push-notifications (~> 1.1)
-  rack-attack (~> 6.3.0)
+  rack-attack (~> 6.3.1)
   rack-cors (~> 1.1)
   rack-host-redirect (~> 1.3)
   rack-timeout (~> 0.6)