Merge pull request #18 from jackyzhen/postgres-support Postgres support

Merge pull request #17 from marianogappa/adds_tests Adds tests

Adds goreleaser 

Updates .travis.yml 

Merge pull request #10 from marianogappa/fix_print_race Fixes print race using a mutex

Adds -h --help flag for showing usage. #5 

Relays errors properly. 

Adds usage function.