Add goreleaser config (#107)

Notes for future self:

  - **To run a "local" release:** `goreleaser release --snapshot --clean`
  - **To check configuration file:** `goreleaser check`
  - **To create a new release:** `goreleaser release`

tools.go

@@ -5,5 +5,6 @@ package main
 
 import (
 	_ "github.com/golangci/golangci-lint/cmd/golangci-lint"
+	_ "github.com/goreleaser/goreleaser"
 	_ "golang.org/x/tools/cmd/stringer"
 )