Try parsing HTML even if content-type is empty.

response.go

@@ -4,7 +4,6 @@ import (
 	"github.com/PuerkitoBio/goquery"
 	"net/http"
 	"net/url"
-	"strings"
 )
 
 // Response type wraps http.Response
@@ -27,16 +26,3 @@ func (r *Response) JoinURL(relativeURL string) string {
 	joinedURL := r.Response.Request.URL.ResolveReference(parsedRelativeURL)
 	return joinedURL.String()
 }
-
-func (r *Response) isHTML() bool {
-	if r.Response == nil {
-		return len(r.Body) != 0
-	}
-	contentType := r.Header.Get("Content-Type")
-	for _, htmlContentType := range []string{"text/html", "application/xhtml+xml", "application/vnd.wap.xhtml+xml"} {
-		if strings.Contains(contentType, htmlContentType) {
-			return true
-		}
-	}
-	return false
-}