Replace use of commons-collections with Spring CollectionUtils

closes #971

Signed-off-by: Roy Clarkson <roy.clarkson@broadcom.com>

Author: royclarkson

spring-cloud-open-service-broker-core/src/main/java/org/springframework/cloud/servicebroker/service/events/EventFlowRegistry.java

@@ -19,10 +19,11 @@
 import java.util.ArrayList;
 import java.util.List;
 
-import org.apache.commons.collections.CollectionUtils;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 
+import org.springframework.util.CollectionUtils;
+
 /**
  * Abstract class for defining an event flow registry.
  *
@@ -48,13 +49,13 @@ public abstract class EventFlowRegistry<I, C, E, R, S> {
 	 * @param errorFlows the error flows
 	 */
 	protected EventFlowRegistry(List<I> initializationFlows, List<C> completionFlows, List<E> errorFlows) {
-		if (CollectionUtils.isNotEmpty(initializationFlows)) {
+		if (!CollectionUtils.isEmpty(initializationFlows)) {
 			initializationFlows.forEach((flow) -> this.initializationFlows.add(Mono.just(flow)));
 		}
-		if (CollectionUtils.isNotEmpty(completionFlows)) {
+		if (!CollectionUtils.isEmpty(completionFlows)) {
 			completionFlows.forEach((flow) -> this.completionFlows.add(Mono.just(flow)));
 		}
-		if (CollectionUtils.isNotEmpty(errorFlows)) {
+		if (!CollectionUtils.isEmpty(errorFlows)) {
 			errorFlows.forEach((flow) -> this.errorFlows.add(Mono.just(flow)));
 		}
 	}