Assert return values in test_update_zero_should_commit / conflict

Add the missing [Result.COMMIT] / [Result.CONFLICT] assertions so
that the two regression tests actually verify the expected conflict-set
outcome, not just that the calls do not crash.

test_conflict_set.py

@@ -68,7 +68,7 @@ def test_update_zero_should_commit():
             for i in range(256 - 17, 256):
                 cs2.addWrites(int(1), write(bytes([i])))
             # Scan until first point write
-            cs2.check(read(0, b"\x00", bytes([256 - 17])))
+            assert cs2.check(read(0, b"\x00", bytes([256 - 17]))) == [Result.COMMIT]
 
 
 def test_update_zero_should_conflict():
@@ -81,7 +81,7 @@ def test_update_zero_should_conflict():
             # "zero" is now 2**31 + 100
             cs1.addWrites(2**32 + 101, write(b"", b"\x02"), write(b"\x01"))
             # rangeVersion of \x01 is now 2**31 + 100 ("max" of (2**31 + 100, 2**32 + 101))
-            cs1.check(read(2**32 + 1, b"\x00"))
+            assert cs1.check(read(2**32 + 1, b"\x00")) == [Result.CONFLICT]
             # but 2**32 + 1 ">" 2**31 + 100 , and it incorrectly commits