currently content_type is not passed to Rdf::Reader.for() if options is set and options does not contain content_type. This causes a failure to load the correct Rdf::Reader.
This PR addresses that by passing {content_type: response.content_type} if options.content_type is not set
Coverage remained the same at 94.429% when pulling 59d4093247eca1d9cf0f9133179b5791c15b47e9 on nvdk:fix-rdf-parser into ddf951d03c8af2c9ce589a5667d041e5b137e529 on ruby-rdf:develop.
currently content_type is not passed to Rdf::Reader.for() if options is set and options does not contain content_type. This causes a failure to load the correct Rdf::Reader.
This PR addresses that by passing
{content_type: response.content_type}
if options.content_type is not set