Add a place to inject the HTTP_PORT via environment

Replace lib/http-client to testing http client

Replace default ports in pooled servers if defined

Abstract the testing pb client to a test module

Here we can set the protocol buffer client port to be an env var PB_PORT

Fix connection tests

Some of the http-client/connection tests need to talk directly to the
lib/http-client.js object.
noop in readme to trigger ci build
Merge pull request #201 from wlaurance/abstract-testing-client-ports

Easily allow changing of ports for tests.