Improve local testing/development

[MatousJobanek]

Things that should be improved in Makefiles and README

• How I setup DB so I can run integration tests locally (even without docker)
• I would need that DB for running tenant locally too (even if I don't get much from it but I still would like to be able to do it. See the next item)
• How I run tenant locally so I can at least verify main() starts fine and /status is available.

Something like "make dev" could start a docker container with DB and tenant by default uses it. It's similar to what we have in WIT, Auth, Cluster and other new services created via fabric8-starter.
I can do different thing by using very simple commands:

• "make" - builds binaries
• "make dev" - builds binaries, starts all needed containers (DB and critical dependencies), runs the service locally in DevMode.

Next steps would be (we can take at this later):

• "make dev-openshift" does the same as "make dev" but instead of docker-compose it uses minishift.
• do something about running tenant in Dev Mode locally so we can test stuff beyond /status
  it's OK to split it to smaller sub tasks and do it step by step. To improve it gradually over some time instead of spending too much time on that right now.