chore(deps): update dependency sequelize to v6 [security]

Author: renovate[bot]

package-lock.json

@@ -67,7 +67,7 @@
     "prettier-standard": "15.0.1",
     "promise-sequential": "1.1.1",
     "semantic-release": "15.14.0",
-    "sequelize": "5.22.4",
+    "sequelize": "6.29.0",
     "travis-deploy-once": "5.0.11",
     "tsd-jsdoc": "2.5.0",
     "tslint": "5.20.1",