Upgrade to Bundler 2

Summary

We are still using Bundler 1.x. The new 2.x series include some performance improvements and should not have any breaking changes to our current application.

By moving our main rails application we are not forcing other applications to also use the new bundler (for example GDK) as both 1.x and 2.x can co-exist.

Improvements

Upgrade bundler to the newer 2.x version

You can read more about the 2.x in https://bundler.io/blog/2019/01/03/announcing-bundler-2.html

Risks

There is no automated way of reverting back the lock file, we would have to get it from git and re-do any recent change that we made

Involved components

On rails side this involves only the lock file: Gemfile.lock. We also need to install the new bundler in Omnibus