Bump lockbox from 1.4.1 to 2.0.0

Bumps [lockbox](https://github.com/ankane/lockbox) from 1.4.1 to 2.0.0.
- [Changelog](https://github.com/ankane/lockbox/blob/master/CHANGELOG.md)
- [Commits](ankane/lockbox@v1.4.1...v2.0.0)

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

Signed-off-by: dependabot[bot] <[email protected]>

Gemfile.lock

@@ -134,7 +134,7 @@ GEM
     listen (3.9.0)
       rb-fsevent (~> 0.10, >= 0.10.3)
       rb-inotify (~> 0.9, >= 0.9.10)
-    lockbox (1.4.1)
+    lockbox (2.0.0)
     logger (1.6.1)
     loofah (2.23.1)
       crass (~> 1.0.2)