Bump react-rails from 2.6.2 to 3.2.1

Bumps [react-rails](https://github.com/reactjs/react-rails) from 2.6.2 to 3.2.1.
- [Release notes](https://github.com/reactjs/react-rails/releases)
- [Changelog](https://github.com/reactjs/react-rails/blob/master/CHANGELOG.md)
- [Commits](reactjs/react-rails@v2.6.2...v3.2.1)

---
updated-dependencies:
- dependency-name: react-rails
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

Gemfile.lock

@@ -446,7 +446,7 @@ GEM
       ffi (~> 1.0)
     rdoc (6.12.0)
       psych (>= 4.0.0)
-    react-rails (2.6.2)
+    react-rails (3.2.1)
       babel-transpiler (>= 0.7.0)
       connection_pool
       execjs
@@ -544,7 +544,7 @@ GEM
     stringio (3.1.3)
     temple (0.10.0)
     thor (1.3.2)
-    tilt (2.0.11)
+    tilt (2.6.0)
     timecop (0.9.10)
     timeout (0.4.3)
     tinymce-rails (6.3.1)
@@ -574,7 +574,7 @@ GEM
     websocket-extensions (0.1.5)
     xpath (3.2.0)
       nokogiri (~> 1.8)
-    zeitwerk (2.7.1)
+    zeitwerk (2.7.2)
 
 PLATFORMS
   ruby