Fix memory leaks (update redis)

[Uxio0]

• Update redis to v4.1.2
• Set version 4.0.2

What was wrong?

There's a memory leak on production services that we don't observe on staging. The only difference is the redis version

How was it fixed?

Update redis

[coveralls]

Coverage increased (+0.2%) to 88.83% when pulling efa4df0 on hotfix into 3ade858 on master.