Remove pry loading for non-development environments

[alexanderadam]

Currently pry and pry-nav are just available as development dependencies which makes sense.

But the moment Logger is loaded it tries to require pry. and will fail of couse if the project don't have pry as a dependency:

freighter configure

bundler: failed to load command: freighter (/home/user/.rbenv/versions/2.6.0/bin/freighter)
LoadError: cannot load such file -- pry
  /home/user/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/freighter-0.2.6/lib/freighter/logger.rb:2:in `require'
  /home/user/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/freighter-0.2.6/lib/freighter/logger.rb:2:in `<top (required)>'
  /home/user/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/freighter-0.2.6/lib/freighter.rb:2:in `require'
  /home/user/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/freighter-0.2.6/lib/freighter.rb:2:in `block in <top (required)>'
  /home/user/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/freighter-0.2.6/lib/freighter.rb:1:in `each'
  /home/user/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/freighter-0.2.6/lib/freighter.rb:1:in `<top (required)>'
  /home/user/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/freighter-0.2.6/bin/freighter:5:in `require'
  /home/user/.rbenv/versions/2.6.0/lib/ruby/gems/2.6.0/gems/freighter-0.2.6/bin/freighter:5:in `<top (required)>'
  /home/user/.rbenv/versions/2.6.0/bin/freighter:23:in `load'
  /home/user/.rbenv/versions/2.6.0/bin/freighter:23:in `<top (required)>'