Plaso requires redis 4.2

[aarontp]

Plaso has a dependency check and even if you're not using Redis as a backend it still checks the version and currently has an old version (4.2) pinned. For now we are going to pin the Turbinia version of redis as well, but since we don't use this dependency in Plaso, it would be nice if we didn't have to do that. This is to track the longer term fix for this.

There is a --no_dependencies_check flag, but it would be nice not to have to use this because it would still be able to check other real dependency problems.

I filed this on the Plaso side: https://github.com/log2timeline/plaso/issues/4179