Use File::PATH_SEPARATOR for GEM_PATH
Merge pull request #257 from opscode/jdmundrawala/gem-path-sep

Use File::PATH_SEPARATOR for GEM_PATH
Refactor shell_init to allow for exports in different types of shells
Added .ruby-version to gitignore
Added powershell to chef shell-init
Added powershell to supported shell in spec
Posh is powershell in chef shell-init