support custom redis-cli arguments

[hiberabyss]

Could use the global variable to specify custom argument like --no-auth-warning

[guruor]

@hiberabyss I too was looking for some option to send extra params for cluster mode.
After some digging, I found this related issue which solves the problem with url params, which I think is better approach.
#96

Sample code in clickhouse adapter: Reference

[hiberabyss]

Params in URI isn't convenient since the params need be added in every URI.