Bump redis from 2.8.0 to 3.1.2 in /docs
Bump redis from 2.8.0 to 3.1.2 in /docs

Bumps [redis](https://github.com/NodeRedis/node-redis) from 2.8.0 to 3.1.2.
- [Release notes](https://github.com/NodeRedis/node-redis/releases)
- [Changelog](https://github.com/NodeRedis/node-redis/blob/master/CHANGELOG.md)
- [Commits](https://github.com/NodeRedis/node-redis/compare/v.2.8.0...v3.1.2)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
foxdonut/meiosis-tracer,foxdonut/meiosis-tracer