try a more robust way to indentify if Redis is running in e2e tests

.circleci/config.yml

@@ -61,15 +61,18 @@ orbs:
           - run:
               name: Wait for the Oracle to start
               command: |
-                set +e
                 i=0
-                while [[ $(redis-cli GET << parameters.redis-key >> ) ]]; do
-                  ((i++))
-                  if [ "$i" -gt 30 ]
-                  then
-                    exit -1
+                while : 
+                do
+                  (echo > /dev/tcp/127.0.0.1/6379) >/dev/null 2>&1
+                  if [[ $? -eq 0 ]]; then
+                    break
+                  fi
+                  ((i++))
+                  if [ "$i" -gt 30 ]; then
+                    echo "Redis has not open the port"
+                    exit 1
                   fi
-
                   echo "Sleeping..."
                   sleep 3
                 done