Tests: now autoload tests from /worlds/*/test (#1318)

Co-authored-by: black-sliver <59490463+black-sliver@users.noreply.github.com>

worlds/zillion/test/__init__.py

@@ -0,0 +1,20 @@
+from typing import cast
+from test.TestBase import WorldTestBase
+from worlds.zillion import ZillionWorld
+
+
+class ZillionTestBase(WorldTestBase):
+    game = "Zillion"
+
+    def ensure_gun_3_requirement(self) -> None:
+        """
+        There's a low probability that gun 3 is not required.
+
+        This makes sure that gun 3 is required by making all the canisters
+        in O-7 (including key word canisters) require gun 3.
+        """
+        zz_world = cast(ZillionWorld, self.multiworld.worlds[1])
+        assert zz_world.zz_system.randomizer
+        for zz_loc_name, zz_loc in zz_world.zz_system.randomizer.locations.items():
+            if zz_loc_name.startswith("r15c6"):
+                zz_loc.req.gun = 3