new unit tests, hehe 67

Signed-off-by: galeon <dertiellis@gmail.com>

tests/fixtures/versions/fabric-loader-0.15.0-1.20.1.json

@@ -0,0 +1,9 @@
+{
+  "id": "fabric-loader-0.15.0-1.20.1", "inheritsFrom": "1.20.1", "type": "release",
+  "mainClass": "net.fabricmc.loader.impl.launch.knot.KnotClient",
+  "arguments": {"game": [], "jvm": ["-DFabricMcEmu= net.minecraft.client.main.Main "]},
+  "libraries": [
+    {"name": "net.fabricmc:fabric-loader:0.15.0", "url": "https://maven.fabricmc.net/"},
+    {"name": "com.mojang:brigadier:9.9.9", "url": "https://maven.fabricmc.net/"}
+  ]
+}