Remove obsolete pattern properties from track's config.json file. (exercism#1952)

ErikSchierboom · web-flow · commit b5671c025def · 2021-07-08T13:16:41.000+02:00
diff --git a/config.json b/config.json
@@ -18,7 +18,6 @@
   "test_runner": {
     "average_run_time": 12.0
   },
-  "solution_pattern": "reference",
   "files": {
     "solution": [
       "src/main/java/%{pascal_slug}.java"
