Release v1.3.0

Fix golints

Bug fix in pbSerializer and code clean up (#61)

This PR fixes the buildMessageIndexes function where the indexBuf would
not get the result of the loop variable. This also improves the
packer_utils to use big endian instead of small to provide consistency
throughout the code.

Add schema registry integration (#59)

This is an integration for Nats Kafka bridge with Confluent compatible
schema registries. The functionality uses srclient as the schema
registry client and adds support for sending and receiving Avro, JSON
and protobuf encoded messages. There are unit tests added as well.

Resolves #13

Run go mod tidy

Update Shopify/sarama to 1.29.1

This fixes an int overflow issue for 32-bit arches.

Support connections with SASL and TLS (#30)

Currently, users can only choose between SASL and TLS insecure skip verify and
full TLS. This change allows users to use SASL with full TLS.