PR: Flatten folding regions (#893)

Author: andfoy

pyls/python_ls.py

@@ -287,7 +287,7 @@ def signature_help(self, doc_uri, position):
         return self._hook('pyls_signature_help', doc_uri, position=position)
 
     def folding(self, doc_uri):
-        return self._hook('pyls_folding_range', doc_uri)
+        return flatten(self._hook('pyls_folding_range', doc_uri))
 
     def m_text_document__did_close(self, textDocument=None, **_kwargs):
         workspace = self._match_uri_to_workspace(textDocument['uri'])