Circular dependency warning

[mattbrictson]

Running rake on the project with Ruby warnings enabled shows this message:

lib/airbrussh/formatter.rb:1: warning: loading in progress, circular require considered harmful - lib/airbrussh.rb
  from gems/rake-12.0.0/lib/rake/rake_test_loader.rb:4:in  `<main>'
  from gems/rake-12.0.0/lib/rake/rake_test_loader.rb:4:in  `select'
  from gems/rake-12.0.0/lib/rake/rake_test_loader.rb:15:in  `block in <main>'
  from gems/rake-12.0.0/lib/rake/rake_test_loader.rb:15:in  `require'
  from test/airbrussh/capistrano/tasks_test.rb:1:in  `<top (required)>'
  from test/airbrussh/capistrano/tasks_test.rb:1:in  `require'
  from test/minitest_helper.rb:9:in  `<top (required)>'
  from test/minitest_helper.rb:9:in  `require'
  from lib/airbrussh.rb:2:in  `<top (required)>'
  from lib/airbrussh.rb:2:in  `require'
  from lib/airbrussh/formatter.rb:1:in  `<top (required)>'
  from lib/airbrussh/formatter.rb:1:in  `require'