Added support for mananged-keys-directory config option.  Named process was constantly at 100% (or greater) CPU before defining this option.  BIND documentation seems to indicate this defaults to the working directory ("directory" config option), however I had to explicitly declare it in order for the mkeys file to be created.
Give module user the ability to revert back to (Puppet default) service restart rather than reload.  Did not change the default behavior to do service reload.  This dovetails with the work done to add managed-keys-directory config option.  Had to manually restart named for the option to be realized.  This isn't practical in my environment.
Setting $managed_keys_directory = undef, rather than $directory.
One too many @'s before managed_keys_directory in the template.
Merge pull request #19 from asedge/master

Adding managed-keys-directory option as well as giving module user ability to use service restart rather than service reload (at their own risk of course).