(maint) Remove unused variables

The version variable is not used in the fetch_pe_on_windows method (and
hopefully wasn't producing a useful side effect...)

The removed snapshot and box keys in HOST_DEFAULTS were being
overwritten by later keys in the same hash definition and were producing
warnings...

lib/beaker-pe/install/pe_utils.rb

@@ -177,7 +177,6 @@ def fetch_pe_on_mac(host, opts)
         def fetch_pe_on_windows(host, opts)
           path = host['pe_dir'] || opts[:pe_dir]
           local = File.directory?(path)
-          version = host['pe_ver'] || opts[:pe_ver_win]
           filename = "#{host['dist']}"
           extension = ".msi"
           if local

spec/helpers.rb

@@ -26,8 +26,6 @@ def fog_file_contents
 
 module HostHelpers
   HOST_DEFAULTS = { :platform => 'unix',
-                    :snapshot => 'pe',
-                    :box => 'box_name',
                     :roles => ['agent'],
                     :snapshot => 'snap',
                     :ip => 'default.ip.address',