## What changes were proposed in this pull request?
This PR replaces the old Kafka API to 0.10.0 ones in `KafkaTestUtils`.
The change include:
- `Producer` to `KafkaProducer`
- Change configurations to equalvant ones. (I referred [here](http://kafka.apache.org/documentation.html#producerconfigs) for 0.10.0 and [here](http://kafka.apache.org/082/documentation.html#producerconfigs
) for old, 0.8.2).
This PR will remove the build warning as below:
```scala
[WARNING] .../spark/external/kafka-0-10/src/main/scala/org/apache/spark/streaming/kafka010/KafkaTestUtils.scala:71: class Producer in package producer is deprecated: This class has been deprecated and will be removed in a future release. Please use org.apache.kafka.clients.producer.KafkaProducer instead.
[WARNING] private var producer: Producer[String, String] = _
[WARNING] ^
[WARNING] .../spark/external/kafka-0-10/src/main/scala/org/apache/spark/streaming/kafka010/KafkaTestUtils.scala:181: class Producer in package producer is deprecated: This class has been deprecated and will be removed in a future release. Please use org.apache.kafka.clients.producer.KafkaProducer instead.
[WARNING] producer = new Producer[String, String](new ProducerConfig(producerConfiguration))
[WARNING] ^
[WARNING] .../spark/streaming/kafka010/KafkaTestUtils.scala:181: class ProducerConfig in package producer is deprecated: This class has been deprecated and will be removed in a future release. Please use org.apache.kafka.clients.producer.ProducerConfig instead.
[WARNING] producer = new Producer[String, String](new ProducerConfig(producerConfiguration))
[WARNING] ^
[WARNING] .../spark/external/kafka-0-10/src/main/scala/org/apache/spark/streaming/kafka010/KafkaTestUtils.scala:182: class KeyedMessage in package producer is deprecated: This class has been deprecated and will be removed in a future release. Please use org.apache.kafka.clients.producer.ProducerRecord instead.
[WARNING] producer.send(messages.map { new KeyedMessage[String, String](topic, _ ) }: _*)
[WARNING] ^
[WARNING] four warnings found
[WARNING] warning: [options] bootstrap class path not set in conjunction with -source 1.7
[WARNING] 1 warning
```
## How was this patch tested?
Existing tests that use `KafkaTestUtils` should cover this.
Author: hyukjinkwon <gurwls223@gmail.com>
Closes#14416 from HyukjinKwon/SPARK-16776.
f93ad4fe7c