FIX: FileHelper should prioritize response content-type.

Request to a URL with `.png` extension may return a jpg
instead causing us to attach the wrong extension to an
upload.

spec/components/file_helper_spec.rb

@@ -12,7 +12,6 @@ describe FileHelper do
   end
 
   describe "download" do
-
     it "correctly raises an OpenURI HTTP error if it gets a 404 even with redirect" do
       url = "http://fourohfour.com/404"
       stub_request(:get, url).to_return(status: 404, body: "404")
@@ -69,6 +68,24 @@ describe FileHelper do
       )
       expect(tmpfile.read[0..5]).to eq("GIF89a")
     end
+
+    describe 'when url is a jpeg' do
+      let(:url) { "https://eviltrout.com/trout.jpg" }
+
+      it "should prioritize the content type returned by the response" do
+        stub_request(:get, url).to_return(body: png, headers: {
+          "content-type": "image/png"
+        })
+
+        tmpfile = FileHelper.download(
+          url,
+          max_file_size: 10000,
+          tmp_file_name: 'trouttmp'
+        )
+
+        expect(File.extname(tmpfile)).to eq('.png')
+      end
+    end
   end
 
 end