feat: add upstream and verbose flags to command line interface

feat: add upstream support allowing to chain cache servers if needed
fix: tweaked garbage collection to be better

steamcache/logger/logger.go

@@ -6,4 +6,8 @@ import (
 	"github.com/rs/zerolog"
 )
 
+func init() {
+	zerolog.SetGlobalLevel(zerolog.InfoLevel)
+}
+
 var Logger = zerolog.New(zerolog.ConsoleWriter{Out: os.Stderr}).With().Timestamp().Logger()