OpenMAMA-6.3.0-rc1

This is a maintenance release which fixes several outstanding bugs and introduces some new functionality.

• OpenMAMA middleware "base" bridge now included to reduce the overall development required to write a new middleware bridge.
• Builds now performed using docker environment
• New docker image on dockerhub: https://hub.docker.com/r/openmama/openmama (see: https://github.com/OpenMAMA/OpenMAMA/tree/OpenMAMA-6.3.0/docker for documentation)
• Several other bugs and enhancements

For a complete list of all 20 issues included in this release, please see here: https://github.com/OpenMAMA/OpenMAMA/milestone/10?closed=1