FIXES #3229 Require bundler 2.3.4+ to fix deprecation warning

[tlehman]

Upgrading to bundler 2.3.4 or above fixes the

Calling `DidYouMean::SPELL_CHECKERS.merge!(error_name => spell_checker)' has been deprecated. Please call `DidYouMean.correct_error(error_name, spell_checker)' instead.

error. In order to apply this change with a locally built bolt:

1. delete Gemfile.lock
2. delete modules/**/*
3. upgrade bundler gem install bundler -v '2.3.4'
4. confirm that bundle -v returns the correct version
5. if 4 is confirmed, then
   5a. bundle install
   5b. bundle exec r10k puppetfile install Puppetfile

[tlehman]

The failed task said

Your Ruby version is 2.7.8, but your Gemfile specified 2.7.7
Error: The process '/opt/hostedtoolcache/Ruby/2.7.8/x64/bin/bundle' failed with exit code 18

fixing now.

[justinstoller]

I didn't know you could set the bundler version like that, is it well supported?

[justinstoller]

Seems to do what it says on the tin.