Sidekiq 7 compatibility

[damuz91]

Even tho it seems guys have managed to make it to work with Sidekiq 7, the gem in the latest version does not seem to have included this changes.

Therefore, I used the ref to the commit where all the fixes where pushed and now I got sidekiq-batch working with Sidekiq 7.

gem 'sidekiq-batch', git: '[email protected]:breamware/sidekiq-batch.git', ref: 'f2ef0289ea23e652797741de96506957535099ff'

I see this related issue, but it's been closed.

Please release a new version, and off course, thanks for a great gem!