librdkafka buildpack

This buildpack compiles librdkafka for use with node-rdkafka.

• This buildpack expects that you have at least the heroku standard nodejs buildpack. This buildpack should come first so that librdkafka gets installed before yarn install node-rdkafka gets run.
• Set up like so:

heroku buildpacks:set https://github.com/HDVInsurance/heroku-buildpack-librdkafka.git