Add formula for kafka-0.8.0.

Added a formula for kafka-0.8.0. 

Also see homebrew pull request https://github.com/Homebrew/homebrew/pull/25109 which builds from source.  This does an install of prebuilt Java binaries instead, moving this formula to homebrew-binary per request. 

Supersedes:  https://github.com/Homebrew/homebrew/pull/26158