Merge branch 'improvements'

* improvements:
  Increment to cookbook version 1.4.0
  Fix Rubocop Infractions
  Enhance Beaver Tail Resource
  Add support for run as a custom user
  Default logstash_version to 1
  Upgrade to version 31
Merge branch 'improvements'

* improvements:
  Add confd directory to config
Support hashes for add_field/add_field_env
Add attribute for default tail format value

- maintain backwards compatibility but allow the field to be nilled out.
Use nil check on format instead of empty?

- empty? is not defined on NilClass
Merge branch 'master' into improvements

* master:
  Use nil check on format instead of empty?
  Add attribute for default tail format value
  Support hashes for add_field/add_field_env