Redis: separate test files for redis
Presence: better handling of stringer interface
Redis: change prefix
Redis: new exported error for invalid ids
Redis: change inactiveduration to a string
Redis: unify method calls
Redis: defer conn closing for redis
Redis: fix grammer
Redis: more descriptive errors
Redis: map statuses to Status struct
Redis: create a new error for invalid status response
Redis: better error handling
Example: read redis uri from env var
Redis: read redis uri from env var
Redis: one var, rule em all
Redis: re-order funcs
Redis: get ids from a singleton