support REDIS_PASSWORD env variable

[lanphan]

Check List

• Tests has been run in packages where changes made if available
• Linter has been run for changed code
• Tests for the changes have been added if not covered yet
• Docs have been added / updated if required

Issue Reference this PR resolves

[For example #12]

Description of Changes Made (if issue reference is not provided)
As my Redis instance has password, I did add configuration for Redis here to support password.

[Description goes here]

[paveltiunov]

@lanphan Hey Lan! Overall looks great! Did you have a chance to test it without providing any env variables?

[lanphan]

Hi @paveltiunov pave,
Not yet ... let I check right now and let you know.

[lanphan]

Hi @paveltiunov ,
It works with configuration below:

1. docker-compose.yml starts official redis container:

    redis-test:
      image: redis:latest
      restart: unless-stopped
      networks:
        - backend

2. .env file of cubejs only with REDIS_URL:

REDIS_URL=redis://redis-test:6379/0

3. runs Playground ok, can query and display chart well.

[paveltiunov]

@lanphan Sounds great! Thanks again!