build(deps): bump sendgrid-actionmailer from 3.1.1 to 3.2.0

Bumps [sendgrid-actionmailer](https://github.com/eddiezane/sendgrid-actionmailer) from 3.1.1 to 3.2.0.
- [Release notes](https://github.com/eddiezane/sendgrid-actionmailer/releases)
- [Changelog](https://github.com/eddiezane/sendgrid-actionmailer/blob/master/CHANGELOG.md)
- [Commits](https://github.com/eddiezane/sendgrid-actionmailer/commits)

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

Author: dependabot[bot]

Gemfile.lock

@@ -371,9 +371,9 @@ GEM
     selenium-webdriver (3.142.7)
       childprocess (>= 0.5, < 4.0)
       rubyzip (>= 1.2.2)
-    sendgrid-actionmailer (3.1.1)
+    sendgrid-actionmailer (3.2.0)
       mail (~> 2.7)
-      sendgrid-ruby (~> 6.0)
+      sendgrid-ruby (~> 6.4)
     sendgrid-ruby (6.4.0)
       ruby_http_client (~> 3.4)
     sexp_processor (4.15.0)