updated plugin.pp to fix issue #197
removed str2bool because it should not be necessary and broke if defined by default value as bool:true
Merge pull request #241 from zanloy/fixissue197

Fixissue197
Revert "Fixissue197"
Merge pull request #242 from sensu/revert-241-fixissue197

Revert "Fixissue197"
Added Puppet 3.7.0