Changle file name/extension from .yaml to .yml

Status Job ID Name Coverage
  Syntax
canceled #140
syntax lint metadata_lint check:symlinks check:git_ignore check:dot_underscore check:test_file rubocop-Ruby 2.5.3-Puppet ~> 6

 
  Unit
canceled #142
parallel_spec-Ruby 2.4.5-Puppet ~> 5

canceled #141
parallel_spec-Ruby 2.5.3-Puppet ~> 6