As per the recommendation of the Bundler and RubyGems teams:
When developing a gem, use the gemspec method in your Gemfile to avoid
duplication. In general, a gem's Gemfile should contain the Rubygems
source and a single gemspec line. Do not check your Gemfile.lock into
version control, since it enforces precision that does not exist in
the gem command, which is used to install gems in practice. Even if
the precision could be enforced, you wouldn't want it, since it would
prevent people from using your library with versions of its
dependencies that are different from the ones you used to develop the
gem.
Update changes from https://github.com/intercom/intercom-rails/pull/151
As per the recommendation of the Bundler and RubyGems teams: