Apache Bahir 2.0.2 for Apache Spark

Task

[BAHIR-82] - Prepare release based on Apache Spark 2.0.2

Sub-Task

[BAHIR-64] - Add test that Akka streaming connector can receive data
[BAHIR-69] - Clean build between different scala versions

Test

[BAHIR-83] - Flaky test in BasicMQTTSourceSuite
[BAHIR-84] - Build log flooded with test log messages