Pravega - OpenMessaging Benchmark 0.1.0

This is the first release of our OpenMessaging Benchmark fork with Pravega 0.8.0 artifacts. This release corresponds to the code used to execute Pravega and Pulsar experiments in the blog post entitled When speeding makes sense — Fast, consistent, durable and scalable streaming data with Pravega (available at https://blog.pravega.io/2020/10/01/when-speeding-makes-sense-fast-consistent-durable-and-scalable-streaming-data-with-pravega/).