Add SoundCloud to the providers not supporting Auth headers
diff --git a/oauth2.go b/oauth2.go
index 9a02afc..6c69c4d 100644
--- a/oauth2.go
+++ b/oauth2.go
@@ -287,6 +287,7 @@
strings.HasPrefix(tokenURL, "https://api.instagram.com/") ||
strings.HasPrefix(tokenURL, "https://www.douban.com/") ||
strings.HasPrefix(tokenURL, "https://api.dropbox.com/") ||
+ strings.HasPrefix(tokenURL, "https://api.soundcloud.com/") ||
strings.HasPrefix(tokenURL, "https://www.linkedin.com/") {
// Some sites fail to implement the OAuth2 spec fully.
return false