So now I have finally deployed my rails application and got past the prerequisite problem using the bundler. Will it now run? Of course not. Now it is trying to connect to a relational database, even though I don't use one. For reasons I do not understand, running the bundler has changed the behavior of my application. It appears to be running some more aggressive start-up initialization that wants to connect to the database I don't have. I wasted many more hours on this and even tried to get help from the friendly crowd at stack overflow.
You might think this proves the value of a PaaS platform, since I did not have these problems with OpenShift, CloudFoundry or Heroku. Why did those work? My guess is that the reason they worked is that they load up a "kitchen sink" image with everything in it including the relational database interfaces I don't want or need. I'm guessing that if I loaded them up too, my app might actually work as it did before packaging. But I have a better solution .... I am done with Rails, hopefully forever. I am going to redo my application using one of the "micro-frameworks" that are much lighter than Rails, or perhaps with nothing more than a basic Rack interface, analogous to the WSGI approach we took with Python.