show that rake oapi:fetch generates wrong output filename

[rw422]

So when I do rake oapi:fetch (regardless of store parameter value) the generated swagger doc is called swagger_doc_swagger_doc.json which looks weird and is probably incorrect.

Failures:

  1) GrapeSwagger::Rake::OapiTasks#file store given boolean true api has version returns versioned swagger_doc.json
     Failure/Error: expect(File.basename(subject.send(:file, docs_url))).to eq('swagger_doc_v1.json')

       expected: "swagger_doc_v1.json"
            got: "swagger_doc_swagger_doc.json"

       (compared using ==)
     # ./spec/lib/oapi_tasks_spec.rb:160:in `block (6 levels) in <top (required)>'

  2) GrapeSwagger::Rake::OapiTasks#file store given name given api has version returns versioned oapi_doc.json
     Failure/Error: expect(File.basename(subject.send(:file, docs_url))).to eq('oapi_doc_v1.json')

       expected: "oapi_doc_v1.json"
            got: "oapi_doc_swagger_doc.json"

       (compared using ==)
     # ./spec/lib/oapi_tasks_spec.rb:175:in `block (6 levels) in <top (required)>'

  3) GrapeSwagger::Rake::OapiTasks#file no store given api has version returns versioned swagger_doc.json
     Failure/Error: expect(File.basename(subject.send(:file, docs_url))).to eq('swagger_doc_v1.json')

       expected: "swagger_doc_v1.json"
            got: "swagger_doc_swagger_doc.json"