Fix typo

Closes #29

README.md

@@ -15,7 +15,7 @@ import gleeunit/should
 
 pub fn send_request() {
   // Prepare a HTTP request record
-  let assert Ok(request) =
+  let assert Ok(req) =
     request.to("https://test-api.service.hmrc.gov.uk/hello/world")
 
   // Send the HTTP request to the server