Adds debug flag to testrpc command for better debugging of intermitte…

[carrollgt91]

…nt docker issues.

Everywhere we've been running testrpc locally, I've just replaced the docker-compose.yml config to use this dockerfile and build it dynamically,

i.e.

  testrpc:
    build:
      context: ../../Sonar/
      dockerfile: Dockerfile.testrpc

This should help us debug #13