add test

tests/set_oauthbearer_token.phpt

@@ -0,0 +1,24 @@
+--TEST--
+Produce, consume
+--SKIPIF--
+<?php
+require __DIR__ . '/integration-tests-check.php';
+--FILE--
+<?php
+require __DIR__ . '/integration-tests-check.php';
+
+$conf = new SimpleKafkaClient\Configuration();
+$conf->set('metadata.broker.list', getenv('TEST_KAFKA_BROKERS'));
+$conf->set('security.protocol', 'SASL_PLAINTEXT');
+$conf->set('sasl.mechanisms', 'OAUTHBEARER');
+
+$conf->setErrorCb(function($kafka, $errorCode, $errorString) {
+    var_dump($errorString);
+});
+
+$producer = new SimpleKafkaClient\Producer($conf);
+$producer->setOAuthBearerToken('token', 100000 + microtime() * 1000, 'principal', ['test'=>'key']);
+$producer->poll(-1);
+echo 'Done';
+--EXPECT--
+Done