MINOR: Update vagrant/tests readme (#9650)

Reviewers: Chia-Ping Tsai <chia7712@gmail.com>

tests/README.md

@@ -11,7 +11,10 @@ Running tests using docker
 Docker containers can be used for running kafka system tests locally.
 * Requirements
   - Docker 1.12.3 (or higher) is installed and running on the machine.
-  - Test require that Kafka, including system test libs, is built. This can be done by running ./gradlew clean systemTestLibs
+  - Test requires that Kafka, including system test libs, is built. This can be done by running
+```
+./gradlew clean systemTestLibs
+```
 * Run all tests
 ```
 bash tests/docker/run_tests.sh
@@ -547,8 +550,10 @@ Where are the unit tests?
 * The kafkatest unit tests are located under kafka/tests/unit
 
 How do I run the unit tests?
-* cd kafka/tests # The base system test directory
-* python3 setup.py test
+```bash
+$ cd kafka/tests # The base system test directory
+$ python3 setup.py test
+```
 
 How can I add a unit test?
 * Follow the naming conventions - module name starts with "check", class name begins with "Check", test method name begins with "check"

vagrant/README.md

@@ -5,10 +5,12 @@ Using Vagrant to get up and running.
 1) Install Virtual Box [https://www.virtualbox.org/](https://www.virtualbox.org/)
 2) Install Vagrant >= 1.6.4 [https://www.vagrantup.com/](https://www.vagrantup.com/)
 3) Install Vagrant Plugins:
+```
+$ vagrant plugin install vagrant-hostmanager
 
-    $ vagrant plugin install vagrant-hostmanager
-    # Optional
-    $ vagrant plugin install vagrant-cachier # Caches & shares package downloads across VMs
+# Optional, to caches & shares package downloads across VMs
+$ vagrant plugin install vagrant-cachier
+```
 
 In the main Kafka folder, do a normal Kafka build:
 
@@ -48,13 +50,11 @@ To log into one of the machines:
 
     vagrant ssh <machineName>
 
-You can access the brokers and zookeeper by their IP or hostname, e.g.
+You can access the brokers by their IP or hostname, e.g.
 
-    # Specify ZooKeeper node 1 by it's IP: 192.168.50.11
-    bin/kafka-topics.sh --create --zookeeper 192.168.50.11:2181 --replication-factor 3 --partitions 1 --topic sandbox
-
-    # Specify brokers by their hostnames: broker1, broker2, broker3
-    bin/kafka-console-producer.sh --broker-list broker1:9092,broker2:9092,broker3:9092 --topic sandbox
+    # Specify brokers by their hostnames: broker1, broker2, broker3 (or just one of them)
+    bin/kafka-topics.sh --create --bootstrap-server broker1:9092 --replication-factor 3 --partitions 1 --topic sandbox
+    bin/kafka-console-producer.sh --bootstrap-server broker1:9092,broker2:9092,broker3:9092 --topic sandbox
 
     # Specify brokers by their IP: 192.168.50.51, 192.168.50.52, 192.168.50.53
     bin/kafka-console-consumer.sh --bootstrap-server 192.168.50.51:9092,192.168.50.52:9092,192.168.50.53:9092 --topic sandbox --from-beginning