Enable two test runs with multiZk system property (#710)
Enable two test runs with multiZk system property (#710)

We want to achieve horizontal scalability for ZK, meaning we want to allow users to add more ZK deployments and shard based on the ZK read/write path. To test this going forward, we want to be able to execute existing tests in two different environments: 1. single-ZK env, and 2. multi-ZK env.
Changelist:
1. Create two executions for maven-surefire-plugin with multiZk system property
apache/helix,lei-xia/helix,apache/helix,lei-xia/helix,dasahcc/helix,dasahcc/helix,apache/helix,dasahcc/helix,apache/helix,apache/helix,dasahcc/helix,lei-xia/helix,lei-xia/helix,dasahcc/helix,apache/helix,lei-xia/helix,dasahcc/helix,lei-xia/helix