Bump ajv from 6.12.0 to 6.12.6 in /client
Bumps [ajv](https://github.com/ajv-validator/ajv) from 6.12.0 to 6.12.6.- [Release notes](https://github.com/ajv-validator/ajv/releases)- [Commits](https://github.com/ajv-validator/ajv/compare/v6.12.0...v6.12.6)...
re #58 first version of react app