v1.3.0

• Add dbmate dump command and automatic schema.sql file generation support (#23)
• Create official docker release image (#21)
• Add default port 3306 for MySQL connections (#13)
• Upgrade to Go 1.9 (#19)
• Separate cmd/dbmate and pkg/dbmate packages for easier importing (#11)
• Add proper cgo build constraints to remove SQLite support in musl binary (#25)
• Migrate to dep for dependency management (#26)