Just checking that _plain_request works with custom headers too

spec/lib/base_spec.rb

@@ -330,6 +330,13 @@ class DummyExample < Flexirest::Base
       EmptyExample._request("http://api.example.com/v1", :get, {}, {headers: {"X-Something": "foo/bar"}})
     end
 
+    it "passes headers if the response is unparsed" do
+      stub_request(:get, "http://api.example.com/v1").
+        with(headers: {'Accept'=>'application/hal+json, application/json;q=0.5', 'Accept-Encoding'=>'gzip;q=1.0,deflate;q=0.6,identity;q=0.3', 'Connection'=>'Keep-Alive', 'Content-Type'=>'application/x-www-form-urlencoded', 'X-Something'=>'foo/bar', 'User-Agent'=>/Flexirest\//}).
+        to_return(status: 200, body: "", headers: {})
+      EmptyExample._plain_request("http://api.example.com/v1", :get, {}, {headers: {"X-Something": "foo/bar"}})
+    end
+
     it "runs callbacks as usual" do
       expect_any_instance_of(Flexirest::Request).to receive(:do_request).with(any_args).and_return(::FaradayResponseMock.new(OpenStruct.new(status:200, response_headers:{}, body:"{\"first_name\":\"Billy\"}")))
       expect(EmptyExample).to receive(:_callback_request).with(any_args).exactly(2).times