Bump pusher from 1.3.1 to 1.3.2 (forem#1099) [ci skip]

Bumps [pusher](https://github.com/pusher/pusher-http-ruby) from 1.3.1 to 1.3.2.
- [Release notes](https://github.com/pusher/pusher-http-ruby/releases)
- [Changelog](https://github.com/pusher/pusher-http-ruby/blob/master/CHANGELOG.md)
- [Commits](pusher/pusher-http-ruby@v1.3.1...v1.3.2)

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

Gemfile.lock

@@ -632,7 +632,7 @@ GEM
       activesupport (>= 3.0.0)
     pundit-matchers (1.6.0)
       rspec-rails (>= 3.0.0)
-    pusher (1.3.1)
+    pusher (1.3.2)
       httpclient (~> 2.7)
       multi_json (~> 1.0)
       pusher-signature (~> 0.1.8)