Fix camelcase -> dasherise issue
Fix camelcase -> dasherise issue

Work around the fact that inflection.dasherise does only work from the
underscored state

Referring to
https://github.com/django-json-api/django-rest-framework-json-api/commit/5b6456763ed7cdd51660d5293b66cd899bee7a91#commitcomment-13266779

django-json-api/django-rest-framework-json-api,django-json-api/rest_framework_ember,leifurhauks/django-rest-framework-json-api,django-json-api/django-rest-framework-json-api,hnakamur/django-rest-framework-json-api,Instawork/django-rest-framework-json-api,leo-naeka/django-rest-framework-json-api,pombredanne/django-rest-framework-json-api,scottfisk/django-rest-framework-json-api,abdulhaq-e/django-rest-framework-json-api,schtibe/django-rest-framework-json-api,martinmaillard/django-rest-framework-json-api,lukaslundgren/django-rest-framework-json-api,kaldras/django-rest-framework-json-api,leo-naeka/rest_framework_ember