Bump ajv from 6.1.1 to 6.2.1
Bump ajv from 6.1.1 to 6.2.1

Bumps [ajv](https://github.com/epoberezkin/ajv) from 6.1.1 to 6.2.1.
- [Commits](https://github.com/epoberezkin/ajv/compare/v6.1.1...v6.2.1)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@dependabot.com>
Nevon/express-physical,Nevon/express-physical