Allow user to disable auto reshim with environment variable

[ChristianLee-Jobber]

Intro

For this line of code here, allow users to skip it with an environment variable. For example:

module ReshimInstaller
  def install(options)
    super
    `asdf reshim ruby` unless ENV["ASDF_SKIP_RESHIM"]
  end
end

Context

I have modularized my code and broken it off into separate gems/engines that all live near the main app. The folder structure resembles the following:

app/
bin/
build/
...
engines/
  engine1/
    app/
    ...
    Gemfile
...
gems/
  gem1/
    ...
    lib/

In order to better manage these gems/ engines which have some interdependencies, I have written a script that can loop through all gems and run bundler commands like bundle update ..., and bundle install.

When using a tool like rbenv, this script will run in a couple of minutes. When using asdf, it takes ~15 minutes, because asdf is calling reshim for every gem/ engine where it will run the bundler command. Allowing an easy way to disable the automatic reshim would be extremely helpful.