Fix to_yaml options parameter

[alexjfisher]

Use Ruby 2.5's transform_keys method to symbolize the keys in the
options parameter before passing to Ruby's to_yaml function.

Note, this requires Puppet 6 and above for the required Ruby version to
be available on both the agent (for puppet apply) and the server
(Puppetserver 6 ships with JRuby 9.2.x which is Ruby 2.5 compatible).

Also fixed up the docs of the to_json function for better consistency
between the two functions.

[CLAassistant]

All committers have signed the CLA.

[puppet-community-rangefinder]

to_json is a function

Breaking changes to this file MAY impact these 14 modules (near match):

• simp-tlog
• arcaik-webhook
• ffquintella-dockerapp_adrapi
• puppet-nomad
• example42-tp
• opuscodium-firefox
• call-workstation
• choria-choria
• openstack-tripleo
• pcfens-filebeat
• bzed-dehydrated
• codingfuture-cfwebapp
• example42-psick
• aursu-kubeinstall

to_yaml is a function

Breaking changes to this file MAY impact these 35 modules (near match):

• devsec-suricata
• liger1978-netdata
• choria-prometheus_streams
• cheehuan-node_info
• kclnmssys-exim
• tailoredautomation-etcd
• choria-stream_replicator
• dylanratcliffe-external_data
• jonhattan-drush
• example42-psick
• ploperations-profile_metadata
• treydock-oxidized
• kobybr-apmserver
• puppet-puppetwebhook
• example42-tp
• sensu-sensu
• call-workstation
• maany-simple_grid
• theforeman-puppet
• gerardkok-ejbca
• walkamongus-atlantis
• slauger-metricbeat
• codingfuture-cfdb
• osc-openondemand
• choria-choria
• slauger-filebeat
• maeq-thanos
• codingfuture-cfwebapp
• puppet-hyperglass
• puppetlabs-kubernetes
• puppet-prometheus
• codingfuture-cfmetrics
• openstack-ceilometer
• openstack-cloudkitty
• aursu-kubeinstall

This module is declared in 318 of 579 indexed public Puppetfiles.

---

These results were generated with Rangefinder, a tool that helps predict the downstream impact of breaking changes to elements used in Puppet modules. You can run this on the command line to get a full report.

Exact matches are those that we can positively identify via namespace and the declaring modules' metadata. Non-namespaced items, such as Puppet 3.x functions, will always be reported as near matches only.