Bump mysql2 from 0.4.9 to 0.5.0

Bumps [mysql2](https://github.com/brianmario/mysql2) from 0.4.9 to 0.5.0.
- [Release notes](https://github.com/brianmario/mysql2/releases)
- [Changelog](https://github.com/brianmario/mysql2/blob/master/CHANGELOG.md)
- [Commits](brianmario/mysql2@0.4.9...0.5.0)

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

Author: dependabot-support

Gemfile.lock

@@ -259,7 +259,7 @@ GEM
       railties (>= 3.0)
     multi_json (1.13.1)
     multipart-post (2.0.0)
-    mysql2 (0.4.9)
+    mysql2 (0.5.0)
     net-scp (1.2.1)
       net-ssh (>= 2.6.5)
     net-ssh (4.2.0)