Bump travis to librdkafka master (to pick up producev())
Bump travis to librdkafka master (to pick up producev())

ctrochalakis/confluent-kafka-go,ctrochalakis/confluent-kafka-go,ctrochalakis/confluent-kafka-go,ctrochalakis/confluent-kafka-go,ctrochalakis/confluent-kafka-go