Person#update_department method

to keep the Person#departments association up to date using simple
department title strings.
WCMS-84
Merge pull request #11 from biola/person_update_department_method

Person#update_department method
Wait to load the elasticsearchable_models

Wait to load the elasticsearchable_models until you actually need them.
It was loading before the custom value of elasticsearch_index gets set.
Merge pull request #14 from biola/fix_buweb_configuration

Wait to load the elasticsearchable_models
hotfix: misplaced @'s
added test and reworked per comments
Merge branch 'master' into auto_generate_mappings

Conflicts:
	lib/buweb_content_models/configuration.rb