Fix invalid mixins json for fake players module (#181)

Author: williambl

…sources/patchwork-extensions.mixins.json …urces/patchwork-fake-players.mixins.jsonpatchwork-fake-players/src/main/resources/patchwork-extensions.mixins.json renamed to patchwork-fake-players/src/main/resources/patchwork-fake-players.mixins.json patchwork-fake-players/src/main/resources/patchwork-extensions.mixins.json renamed to patchwork-fake-players/src/main/resources/patchwork-fake-players.mixins.json

@@ -3,7 +3,7 @@
   "package": "net.patchworkmc.mixin.fakeplayers",
   "compatibilityLevel": "JAVA_8",
   "mixins": [
-    "MixinPlayerAdvancementTracker",
+    "MixinPlayerAdvancementTracker"
   ],
   "injectors": {
     "defaultRequire": 1