fix(deps): bump sequelize from 5.21.5 to 5.21.6

Bumps [sequelize](https://github.com/sequelize/sequelize) from 5.21.5 to 5.21.6.
- [Release notes](https://github.com/sequelize/sequelize/releases)
- [Commits](sequelize/sequelize@v5.21.5...v5.21.6)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

package.json

@@ -20,7 +20,7 @@
     "lodash": "4.17.15",
     "modern-logger": "1.5.55",
     "node-lifx": "0.8.0",
-    "sequelize": "5.21.5",
+    "sequelize": "5.21.6",
     "serverful": "1.4.70",
     "sqlite3": "4.1.1"
   },