Handle task cache collision

[mski-iksm]

[What is this PR?]

• Adding function to handle task cache collision

[Why?]

• When multiple applications run same task at same workspace simultaneously, task cache may collide.
• example
  • Consider situation with same task AA running at application A and application B.
  • In such case, when one task loads the cache while the other is writing, unexpected error may happen.

[How to overcome the problem?]

• Implement cache file lock using redis
  • When gokart write/load/delete cache file, gokart will ask redis to lock file.
  • When lock is taken by other application, gokart will not run write/load/delete and wait for the lock to be released.

[hirosassa]

LGTM! Thanks!

[Hi-king]

@mski-iksm Merged. Thanks for adding great feature!