[Docker] quick fix for SSO - google openid has been deprecated, default to using Curoverse SSO server
Be less presumptuous about the GNU/Linux distribution we are being run
on, and do not try to install ruby >= 1.9.3 automatically.
- Default to using the auth.curoverse.com SSO server. Add instructions
in config.yml.example for using a local SSO server.
- Do not prepopulate the config.yml file generated by build.sh with
random values for _PW and _SECRET variables, let config.rb deal with
that at build time.
- Make config.rb a bit more robust in choosing those values for _PW and
_SECRET by not depending on any particular key order in the config Hash.
Update Docker install documentation:
- suggest use of build.sh to generate config.yml
- reflect now default use of Curoverse SSO server
Only the deepclean Make action should remove the skydns-image and skydock-image files.