Use `lookupvar` to find variables in sensu:: namespace
Merge pull request #183 from hryk/variables_in_template

Use `lookupvar` to find variables in `sensu::` namespace
add puppet 3.5, 3.6 testing
add ruby 2.1 checks
Merge pull request #189 from jlambert121/puppet_vers

add puppet 3.5, 3.6 testing