Bump capybara from 3.7.2 to 3.8.1

Bumps [capybara](https://github.com/teamcapybara/capybara) from 3.7.2 to 3.8.1.
- [Release notes](https://github.com/teamcapybara/capybara/releases)
- [Changelog](https://github.com/teamcapybara/capybara/blob/master/History.md)
- [Commits](teamcapybara/capybara@3.7.2...3.8.1)

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

Gemfile.lock

@@ -57,7 +57,7 @@ GEM
     brakeman (4.3.1)
     builder (3.2.3)
     byebug (10.0.2)
-    capybara (3.7.2)
+    capybara (3.8.1)
       addressable
       mini_mime (>= 0.1.3)
       nokogiri (~> 1.8)