Bump mongoose from 5.6.8 to 5.7.8 in /task

Bumps [mongoose](https://github.com/Automattic/mongoose) from 5.6.8 to 5.7.8.
- [Release notes](https://github.com/Automattic/mongoose/releases)
- [Changelog](https://github.com/Automattic/mongoose/blob/master/History.md)
- [Commits](Automattic/mongoose@5.6.8...5.7.8)

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

Author: dependabot[bot]

task/package.json

@@ -17,7 +17,7 @@
     "@nestjs/microservices": "6.5.3",
     "@nestjs/mongoose": "6.1.2",
     "@nestjs/platform-express": "6.0.0",
-    "mongoose": "5.6.8",
+    "mongoose": "5.7.8",
     "reflect-metadata": "0.1.12",
     "rimraf": "2.6.2",
     "rxjs": "6.3.3"