Play to run containers in dev mode

[benarmston]

• Each container has its source volume mounted to the appropriate location.
• Cluster builder's flask process is started with --debug.
• Visualiser is start with RAILS_ENV=development.
• Metric daemon is started under air.
• The concertim openstack services don't seem to have an easy way to put them in development mode. Perhaps passing debug=True as an argument to driver.py could be made to work for some of them.

Things that could still be improved:

• Better plays for starting/stopping/restarting containers. This would take into account whether the docker-compose.dev.yml file needs to be merged into docker-compose.yml.
• Better support for developing the proxy container. Currently, its not obvious how one would change the nginx configuration and have that picked up by the proxy container. Perhaps that's just a documentation issue, or perhaps we want a better process here too.
• Support for providing vagrant VM with access to the user's editor, git, bash and other configurations. Mounting the entire home directory as a vagrant shared folder is probably not a good idea. We likely all have different ideas of what constitutes a good development environment. Perhaps additional and optional provision scripts that copies items across somehow, e.g., provision-ben.sh, provision-tim.sh etc..

[jamesremuscat]

Is it worth noting the startup race condition in the list of "things that could be improved"? Could possibly be resolved with a Docker healthcheck definition on the visualisation container coupled with depends_on/condition declarations for the relevant services?

EDIT: That's now covered by #86.

[benarmston]

I'm going to merge this to main. It works just fine for me. The documentation can be enhanced for those using VSCode and developing directly on their laptops, but I will leave that up to such users.