Deprecate listIncompleteUploads() and removeIncompleteUploads()

Public methods in MinioClient does not leave incomplete uploads on
failures. Hence `listIncompleteUploads()` and
`removeIncompleteUploads()` are deprecated and will be removed later.

However protected methods `listMultipartUploads()`, `listParts()` and
`abortMultipartUpload()` in MinioClient are available by
inheritance for developers.

api/src/main/java/io/minio/ListMultipartUploadsResponse.java

@@ -0,0 +1,35 @@
+/*
+ * MinIO Java SDK for Amazon S3 Compatible Cloud Storage, (C) 2020 MinIO, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.minio;
+
+import io.minio.messages.ListMultipartUploadsResult;
+import okhttp3.Headers;
+
+/** Response class of MinioClient.listMultipartUploads(). */
+public class ListMultipartUploadsResponse extends GenericResponse {
+  private ListMultipartUploadsResult result;
+
+  public ListMultipartUploadsResponse(
+      Headers headers, String bucket, String region, ListMultipartUploadsResult result) {
+    super(headers, bucket, region, null);
+    this.result = result;
+  }
+
+  public ListMultipartUploadsResult result() {
+    return result;
+  }
+}

api/src/main/java/io/minio/RemoveIncompleteUploadArgs.java → api/src/main/java/io/minio/ListPartsResponse.java

@@ -1,6 +1,5 @@
 /*
- * MinIO Java SDK for Amazon S3 Compatible Cloud Storage,
- * (C) 2020 MinIO, Inc.
+ * MinIO Java SDK for Amazon S3 Compatible Cloud Storage, (C) 2020 MinIO, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,12 +16,20 @@
 
 package io.minio;
 
-public class RemoveIncompleteUploadArgs extends ObjectVersionArgs {
+import io.minio.messages.ListPartsResult;
+import okhttp3.Headers;
 
-  public static Builder builder() {
-    return new Builder();
+/** Response class of MinioClient.listParts(). */
+public class ListPartsResponse extends GenericResponse {
+  private ListPartsResult result;
+
+  public ListPartsResponse(
+      Headers headers, String bucket, String region, String object, ListPartsResult result) {
+    super(headers, bucket, region, object);
+    this.result = result;
   }
 
-  public static final class Builder
-      extends ObjectVersionArgs.Builder<Builder, RemoveIncompleteUploadArgs> {}
+  public ListPartsResult result() {
+    return result;
+  }
 }