Increase Cluster configuration memory for upgrade tests (#585)

Author: Srihari1192

tests/upgrade/raycluster_sdk_upgrade_test.py

@@ -52,8 +52,8 @@ def run_mnist_raycluster_sdk_oauth(self):
                 head_memory=2,
                 worker_cpu_requests=1,
                 worker_cpu_limits=1,
-                worker_memory_requests=1,
-                worker_memory_limits=2,
+                worker_memory_requests=4,
+                worker_memory_limits=4,
                 image=ray_image,
                 write_to_file=True,
                 verify_tls=False,