Bump webmock from 3.7.3 to 3.7.4 (#1428)

Bumps [webmock](https://github.com/bblimke/webmock) from 3.7.3 to 3.7.4.
- [Release notes](https://github.com/bblimke/webmock/releases)
- [Changelog](https://github.com/bblimke/webmock/blob/master/CHANGELOG.md)
- [Commits](bblimke/webmock@v3.7.3...v3.7.4)

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

Gemfile.lock

@@ -237,7 +237,7 @@ GEM
     unicorn (5.5.1)
       kgio (~> 2.6)
       raindrops (~> 0.7)
-    webmock (3.7.3)
+    webmock (3.7.4)
       addressable (>= 2.3.6)
       crack (>= 0.3.2)
       hashdiff (>= 0.4.0, < 2.0.0)