Added fix for missing /etc/puppet/tmp directory error

The tmp directory does not seem to be a standard directory in /etc/puppet (this seems to be the case for ubuntu 12.04 and the rpm package distributed by puppetlabs), so I added a resource to create if it wasn't there. 

Otherwise I get this error:

Error: Cannot create /etc/puppet/tmp/limits_fragments.d; parent directory /etc/puppet/tmp does not exist
Error: /Stage[main]/Limits/File[/etc/puppet/tmp/limits_fragments.d/]/ensure: change from absent to directory failed: Cannot create /etc/puppet/tmp/limits_fragments.d; parent directory /etc/puppet/tmp does not exist