Bump rollbar from 2.16.0 to 2.16.2

Bumps [rollbar](https://github.com/rollbar/rollbar-gem) from 2.16.0 to 2.16.2.
- [Release notes](https://github.com/rollbar/rollbar-gem/releases)
- [Changelog](https://github.com/rollbar/rollbar-gem/blob/master/CHANGELOG.md)
- [Commits](rollbar/rollbar-gem@v2.16.0...v2.16.2)

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

Gemfile.lock

@@ -274,7 +274,7 @@ GEM
       mime-types (>= 1.16, < 3.0)
       netrc (~> 0.7)
     rinku (2.0.4)
-    rollbar (2.16.0)
+    rollbar (2.16.2)
       multi_json
     ruby-pushbullet (0.1.4)
       json