Bump bullet from 6.1.5 to 7.0.0

Bumps [bullet](https://github.com/flyerhzm/bullet) from 6.1.5 to 7.0.0.
- [Release notes](https://github.com/flyerhzm/bullet/releases)
- [Changelog](https://github.com/flyerhzm/bullet/blob/master/CHANGELOG.md)
- [Commits](https://github.com/flyerhzm/bullet/compare/6.1.5...7.0.0)

---
updated-dependencies:
- dependency-name: bullet
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Gemfile.lock

@@ -78,7 +78,7 @@ GEM
       autoprefixer-rails (>= 5.2.1)
       sassc (>= 2.0.0)
     builder (3.2.4)
-    bullet (6.1.5)
+    bullet (7.0.0)
       activesupport (>= 3.0.0)
       uniform_notifier (~> 1.11)
     byebug (11.1.3)
@@ -154,7 +154,7 @@ GEM
       rake
     mini_mime (1.1.2)
     mini_portile2 (2.6.1)
-    minitest (5.14.4)
+    minitest (5.15.0)
     minitest-stub-const (0.6)
     mocha (1.13.0)
     mysql2 (0.5.3)