Update integration tests & remove unnecessary local variable

src/main/kotlin/Service.kt

@@ -35,11 +35,8 @@ class Service(file: String = "app.yml") {
         file,
         useStreamsConfig = true
     )
-
-    private val builder = KafkaTopology(settings).prepare()
     fun run() {
-
-        val stream = KafkaStreams(builder.build(), settings.kafkaStreamsSettings)
+        val stream = KafkaStreams(KafkaTopology(settings).prepare().build(), settings.kafkaStreamsSettings)
         stream.use {
             it.start()
             while (stream.state().isRunning) {

src/test/kotlin/IntegrationTests.kt

@@ -27,7 +27,6 @@ import org.apache.kafka.common.serialization.StringDeserializer
 import org.apache.kafka.common.serialization.StringSerializer
 import org.apache.kafka.streams.TopologyTestDriver
 import org.apache.kafka.streams.test.ConsumerRecordFactory
-import org.apache.logging.log4j.LogManager
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.TestInstance
 import org.junit.jupiter.params.ParameterizedTest
@@ -41,7 +40,6 @@ import java.util.stream.Stream
 
 @TestInstance(TestInstance.Lifecycle.PER_CLASS)
 class IntegrationTests {
-    private val log = LogManager.getLogger("TestLogger")
 
     private val resourcePath = "src/test/resources"
     private fun readFile(fileName: String): String {