Fix types to work with 'puppet generate types'

[treydock]

Pull Request (PR) description

Fix types to work with puppet generate types. These are the errors being produced:

Jan 14 09:45:53 puppet0 r10k-postrun: #033[1;31mError: Failed to load custom type 'grafana_ldap_group_mapping' from '/etc/puppetlabs/code/environments/test_xdmod/modules/grafana/lib/puppet/type/grafana_ldap_group_mapping.rb': uninitialized constant Puppet::Parameter::Boolean#033[0m
Jan 14 09:45:54 puppet0 r10k-postrun: #033[1;31mError: Failed to load custom type 'grafana_ldap_server' from '/etc/puppetlabs/code/environments/test_xdmod/modules/grafana/lib/puppet/type/grafana_ldap_server.rb': uninitialized constant Puppet::Parameter::Boolean#033[0m