Htrace extension for akka http and akka streams

prerequistes:

docker run -d -p 9411:9411 -p 9410:9410 openzipkin/zipkin

running the examples:

sbt examples/run

then choose 1 for http example or 2 for streaming example

The http example will bind to port 8080. point your browesr to localhost:8080/frontend in order to initiate a request.