Quote $@ in templates/razor.erb to avoid whitespace issues

Per:

https://groups.google.com/forum/?hl=en&fromgroups=#!topic/puppet-razor/7Wzo64qlY-M

$@ needs to be quoted to prevent bash from eating the quotes passed on the command line, which in turn causes everything after the space to disappear from --value.

Thank you.
 - Jason Parsons