Make NLP tasks available from AutoML.fit() (#210)

Sequence classification and regression: "seq-classification" and "seq-regression"

Co-authored-by: Chi Wang <wang.chi@microsoft.com>

test/load_args.py

@@ -0,0 +1,8 @@
+def test_load_args_sub():
+    from flaml.nlp.utils import HPOArgs
+
+    HPOArgs.load_args()
+
+
+if __name__ == "__main__":
+    test_load_args_sub()