Bump ajv and request

Bumps [ajv](https://github.com/ajv-validator/ajv) to 6.12.6 and updates ancestor dependency [request](https://github.com/request/request). These dependencies need to be updated together.


Updates `ajv` from 5.5.2 to 6.12.6
- [Release notes](https://github.com/ajv-validator/ajv/releases)
- [Commits](ajv-validator/ajv@v5.5.2...v6.12.6)

Updates `request` from 2.85.0 to 2.88.2
- [Changelog](https://github.com/request/request/blob/master/CHANGELOG.md)
- [Commits](https://github.com/request/request/commits)

---
updated-dependencies:
- dependency-name: ajv
  dependency-type: indirect
- dependency-name: request
  dependency-type: direct:production
...

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