title: How to rubocop for rails without `bundle exec`?
body: <p>I have a rails app running on ruby 2.7.2 with the following in Gemfile:</p>
  <pre class="lang-rb prettyprint-override"><code>group :development, :test do
    gem 'rubocop'
    gem 'rubocop-minitest'
    gem 'rubocop-performance'
    gem 'rubocop-rails'
  end
  </code></pre>
  <p>Have ran <code>bundle install</code> and <code>bundle update</code>.  Anytime I run rubocop in the directory, I get the following:</p>
  <pre><code>Could not find 'activesupport' (&gt;= 4.2.0) among 220 total gem(s)
  </code></pre>
  <p>If I run <code>bundle exec rubocop</code>, all works fine. How can I make this work without the <code>bundle exec</code> part? I run a linter in vim that just calls the executable without the <code>bundle exec</code> and so I'm stuck.</p>
  <p>Interestingly enough, I have a different app on ruby 2.7.2 with the same setup in the Gemfile, and it works fine without prefixing <code>bundle exec.</code></p>