add 'class Chef' outer scope

clearly we need a rubocop rule for this.

this fixes this exception which we were throwing incorrectly:

[2014-10-28T02:57:54+00:00] FATAL: NameError: uninitialized constant
Chef::Application::Exceptions

using 'class Chef::Application' saves a tiny amount of typing and
indentation but does not open up the outer lexical scope and breaks
otherwise working code like this.
Merge pull request #2308 from opscode/lcg/fix-exceptions

Chef::Application outer lexical scope
add 14.04 to supported vagrant distros

10.04 and 14.10 'documented' as broken in the upstream
mysql cookbook
Merge pull request #2315 from opscode/lcg/more-vagrant

add 14.04 to supported vagrant distros
disable workstation tests for aix.
Merge pull request #2320 from ClogenyTechnologies/kd-aix-fixes-wrktn

Disable workstation tests for aix.
Bump to rspec 3.
Use RSpec documentation formatter.
Remove treat_symbols_as_metadata_keys_with_true_values = true, now true by default
Update to RSpec 3.
Use expect syntax.