Merge pull request #4 from adhamsalama/implement-sub-multiple-channels

Implement subscribing to multiple channels

Merge pull request #3 from adhamsalama/implement-pub-sub

Implement pub sub

Merge pull request #2 from adhamsalama/use-rwlock-instead-of-mutix

Use Rwlock instead of Mutex

Merge pull request #1 from adhamsalama/implement-expire-command

Implement EXPIRE command

Add Redis benchmarks