Add SASL handshake negotiation
Add SASL handshake negotiation

This patch adds the mandatory SASL handshake for SASL negotiation.

mailgun/sarama,DataDog/sarama,remerge/sarama,remerge/sarama,vrischmann/sarama,mailgun/sarama,raisemarketplace/sarama,VividCortex/sarama,Shopify/sarama,DataDog/sarama,VividCortex/sarama,Shopify/sarama,raisemarketplace/sarama,vrischmann/sarama