2.1.6

Change Log:

9ddfd52 Upgrade to SF 5.0.6
92c77b3 GH-666: KafkaEmbedded doWithAdmin, addTopics
75375f0 Improve exception message with jar mismatch
66753f3 GH-667: Fix BatchErrorHandler for generic errors
dbfa272 Doc polishing
c5c2765 Upgrade Gradle to 4.7 (2.1.x)
f48ad87 GH-661: Close Producer after beginTransaction fail
9612e88 GH-656: Fix seek on rollback
1f3d7cd GH-652: JsonSerializer add null check for Headers
19ea7f1 KBGH-356: Fix thread naming with no bean name
82eb21f GH-646: Avoid sync when no transaction
1b53c4b GH-646: Transaction Improvements
e6985e8 GH-642: Increase test timeout