chore: update `.gitignore`

Status Job ID Name Coverage
  Syntax
passed #321879
syntax lint metadata_lint check:symlinks check:git_ignore check:dot_underscore check:test_file rubocop-Ruby 2.5.7-Puppet ~> 6

00:01:41

 
  Unit
failed #321881
parallel_spec-Ruby 2.4.5-Puppet ~> 5

00:01:26

failed #321880
parallel_spec-Ruby 2.5.7-Puppet ~> 6

00:01:30

 
Name Stage Failure
failed
parallel_spec-Ruby 2.5.7-Puppet ~> 6 Unit

Tests Failed

1 example, 1 failure

Took 3 seconds
Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1
failed
parallel_spec-Ruby 2.4.5-Puppet ~> 5 Unit
deprecation warnings into errors, giving you the full backtrace.
Tests Failed

1 example, 1 failure

Took 5 seconds
Running after_script
Uploading artifacts for failed job
ERROR: Job failed: exit code 1