Bump phpmailer/phpmailer from 5.2.26 to 6.5.0

Bumps [phpmailer/phpmailer](https://github.com/PHPMailer/PHPMailer) from 5.2.26 to 6.5.0.
- [Release notes](https://github.com/PHPMailer/PHPMailer/releases)
- [Changelog](https://github.com/PHPMailer/PHPMailer/blob/master/changelog.md)
- [Commits](PHPMailer/PHPMailer@v5.2.26...v6.5.0)

---
updated-dependencies:
- dependency-name: phpmailer/phpmailer
  dependency-type: direct:production
...

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

Author: dependabot[bot]

composer.json

@@ -9,7 +9,7 @@
         "respect/validation": "^1.1",
         "slim/csrf": "^0.8.1",
         "slim/flash": "^0.2.0",
-        "phpmailer/phpmailer": "^5.2",
+        "phpmailer/phpmailer": "^6.5",
         "hassankhan/config": "^0.10.0",
         "monolog/monolog": "^1.22",
         "livecontrol/eloquent-datatable": "^0.1.5",