Include GS0.m in tests_gs.py's tests

Author: TiagoCavalcante

examples/symbolic_logic/gries_schneider/test_gs.py

@@ -8,7 +8,7 @@
 
 definitions = Definitions(add_builtin=True)
 
-for i in range(1, 4):
+for i in range(0, 4):
     evaluation = Evaluation(definitions=definitions, catch_interrupt=False)
 
     expr = parse(definitions, MathicsSingleLineFeeder(f"<< GS{i}.m"))