Master requires apt module >= 2.0, not 1.8

[cintiadr]

The include in https://github.com/sensu/sensu-puppet/blob/master/manifests/repo/apt.pp#L31

include  => {
        'src' => false,
      },

is only available for apt module >= 2.*. Before that, the option was called $include_src

I suppose you should update the metadata file.