Upgrading to Sidekiq 7 introduced some incompatibilities with redis-namespace. Keeping the gem would allow some funny combinations like having namespaces enabled for porta but not for sidekiq, since namespaces are not recommended and easily replaceable by Redis numbered databases, we decided to remove the support for Redis namespaces. This will simplify the code, provide stability and reduce tech debt.

Notes for QE:

There's nothing in particular to test here, other than the :namespace parameter being ignored by Redis. However, this issue is a heads up for QE, since wome tests will probably fail after this change.

Release notes:
In 2.15 support for Redis namespaces in the System component (configured via REDIS_NAMESPACE field in the system-redis secret) will be removed. Users must configure either a separate instance of Redis, or, if supported by the Redis provider, a separate numbered database (i.e. with /<number> suffix in the URL) to be used exclusively by the 3scale API Management System component.