Resolve $HOME even if VM spits bogus new lines

Fixes issue #122

lib/vagrant-cachier/cap/linux/composer_path.rb

@@ -7,8 +7,11 @@ module VagrantPlugins
             composer_path = nil
             machine.communicate.tap do |comm|
               return unless comm.test('which php')
+              # on some VMs an extra new line seems to come out, so we loop over
+              # the output just in case
+              composer_path = ''
               comm.execute 'echo $HOME' do |buffer, output|
-                composer_path = output.chomp if buffer == :stdout
+                composer_path += output.chomp if buffer == :stdout
               end
             end
             return "#{composer_path}/.composer/cache"