Move setup steps out of postinst.sh to arvados-server install
The package installation post install script tries to set up the API server by running rake tasks. These fail if the config file hasn't been created or edited yet.
Currently the documentation tells you to write the configuration file first, then install the package. This is counter-intuitive. The previous behavior would create an empty config file but post-install with instructions to edit the config file and reconfigure the package.
Instead, the code to get the API server ready to run should become part of arvados boot, so that the process is:
- install package, with minimal/no post-install script, don't run the service unless it is already configured
- run arvados-boot which will either tell you what you need to do or can go ahead and do necessary setup to start the service