[Bug] Clear all the futures when sync is called. (feast-dev#501)

* Replacing Jedis With Lettuce in ingestion and serving

* Removing extra lines

* Abstacting redis connection based on store

* Check the connection before connecting as lettuce does the retry automatically

* Running spotless

* Throw Exception if the job store config is null

* Handle No enum constant RuntimeException

* Future should be cleared everytime sync is called

ingestion/src/main/java/feast/store/serving/redis/RedisStandaloneIngestionClient.java

@@ -78,8 +78,11 @@ public boolean isConnected() {
   public void sync() {
     // Wait for some time for futures to complete
     // TODO: should this be configurable?
-    LettuceFutures.awaitAll(60, TimeUnit.SECONDS, futures.toArray(new RedisFuture[0]));
-    futures.clear();
+    try {
+      LettuceFutures.awaitAll(60, TimeUnit.SECONDS, futures.toArray(new RedisFuture[0]));
+    } finally {
+      futures.clear();
+    }
   }
 
   @Override