Exclude sign_up from test_all_methods_present

The sign_up method was deprecated in
07a7a8b and removed from the
documentation, but since the method technically still exists (even
though it immediately raises ValueError), that broke a test.

Author: cjwatson

tests/readthedocs/quick_references/test_client_reference.py

@@ -10,5 +10,5 @@ def test_all_methods_present(docs_dir):
     assert len(present_methods) > 0
     for name in dir(TelegramClient):
         attr = getattr(TelegramClient, name)
-        if callable(attr) and not name.startswith('_'):
+        if callable(attr) and not name.startswith('_') and name != 'sign_up':
             assert name in present_methods