remove unused test scripts

Author: glasnt

cloud-sql/mysql/mysql2/package.json

@@ -14,9 +14,7 @@
   "scripts": {
     "start": "node server/server.js",
     "system-test": "c8 mocha -p -j 2 test/server.test.js --timeout=60000 --exit",
-    "system-test-tcp": "c8 mocha -p -j 2 test/server-unix.test.js --timeout=60000 --exit",
-    "system-test-unix": "c8 mocha -p -j 2 test/server-unix.test.js --timeout=60000 --exit",
-    "test": "npm run system-test && npm run system-test-tcp && npm run system-test-unix"
+    "test": "npm run system-test"
   },
   "dependencies": {
     "@google-cloud/cloud-sql-connector": "^1.0.0",