[arrow_alignment] Initialize level_tokens when incrementing index immediately
[arrow_alignment] Initialize level_tokens when incrementing index immediately

Otherwise when we encounter an empty block it'll error out running #each
through the nil array trying to check the alignment of the non-existent arrows.

keeleysam/puppet-lint,yulis/puppet-lint,toby82/puppet-lint,rothsa/puppet-lint,rodjek/puppet-lint,raphink/puppet-lint,paulgeringer/puppet-lint,danzilio/puppet-lint,Rovanion/puppet-lint