Bundler - For the installer, update `bundle_install` method to mimic Blacklight

[ewlarson]

Per @dl-maura

run  bundle install from "."
Fetching gem metadata from https://rubygems.org/..........
There was an error while trying to write to
`/usr/local/bundle/cache/bundler/git`. It is likely that you need to grant write
permissions for that path.

We should try adopting the bundle_install method that Blacklight ships with by default: https://github.com/projectblacklight/blacklight/blob/main/lib/generators/blacklight/install_generator.rb#L43-L49

Also, Bundler.with_clean_env has been deprecated in favor of Bundler.with_unbundled_env

[dl-maura]

So, we do need to switch to unbundled_env, which I will make a PR for, but my error is because of how my docker is setup. I am specifically overriding the clean/default bundler config to have my stuff in a different non-root user folder and when using the clean/unbundled method that gets ignored. For this to work for me, I need to use the with_original_env. There may also be a way to do the install within the Dockerfile that avoids this

[ewlarson]

Closing via #29