librdkafka

Fix SSL handshake busy-loop due to POLLOUT being set in CONNECT state

Sticky assignor: getBalanceScore() did not correctly summarize the score

Assignor: de-conflate owned/assigned partitions (#3306)

Travis: Disable integration tests (since they're flaky on CI) when doing release builds

Sticky assignor: fix balancing and reassignment issues due to incorrect count comparison (#3306)