Rename binary to litestream; add replicate command

cmd/litestream/version.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+)
+
+type VersionCommand struct{}
+
+func (c *VersionCommand) Run(ctx context.Context, args []string) (err error) {
+	fs := flag.NewFlagSet("litestream-version", flag.ContinueOnError)
+	fs.Usage = c.Usage
+	if err := fs.Parse(args); err != nil {
+		return err
+	}
+
+	fmt.Println("litestream", Version)
+
+	return nil
+}
+
+func (c *VersionCommand) Usage() {
+	fmt.Println(`
+Prints the version.
+
+Usage:
+
+	litestream version
+`[1:])
+}