build(deps-dev): bump spring from 2.1.0 to 2.1.1

Bumps [spring](https://github.com/rails/spring) from 2.1.0 to 2.1.1.
- [Release notes](https://github.com/rails/spring/releases)
- [Changelog](https://github.com/rails/spring/blob/master/CHANGELOG.md)
- [Commits](rails/spring@v2.1.0...v2.1.1)

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

Author: dependabot[bot]

Gemfile.lock

@@ -448,7 +448,7 @@ GEM
       thor (~> 1.0)
       tilt (~> 2.0)
       yard (~> 0.9, >= 0.9.24)
-    spring (2.1.0)
+    spring (2.1.1)
     spring-commands-rspec (1.0.4)
       spring (>= 0.9.1)
     statsd-ruby (1.4.0)