[CHEF-4799] Handle non-dupable elements when duping attribute arrays
[CHEF-4946] Don't try to install ruby-shadow on cygwin
Merge branch 'CHEF-4799' of github.com:criteo/chef into contributions-cc-51
Info for CHEF-4799.
Merge branch 'CHEF-4946' of github.com:criteo/chef into contributions-cc-51

Conflicts:
	Gemfile
Info for CHEF-4946.