invalid argument for flag `--ttr

[jpmens]

Building beanstool with go version go1.16.3 darwin/amd64 produces the above diagnostic on sundry commands:

$  ./beanstool stats
invalid argument for flag `--ttr' (expected time.Duration): time: missing unit in duration "60"
Usage:
  beanstool [OPTIONS] stats [stats-OPTIONS]
...


$ ./beanstool tail -t default
invalid argument for flag `--ttr' (expected time.Duration): time: missing unit in duration "60"
Usage:
  beanstool [OPTIONS] tail [tail-OPTIONS]

This small patch fixes that for me:

diff --git cli/put.go cli/put.go
index df7eeb1..0a01f5d 100644
--- cli/put.go
+++ cli/put.go
@@ -12,7 +12,7 @@ type PutCommand struct {
 	Body     string        `short:"b" long:"body" description:"plain text data for the job." required:"true"`
 	Priority uint32        `short:"" long:"priority" description:"priority for the job." default:"1024"`
 	Delay    time.Duration `short:"" long:"delay" description:"delay for the job." default:"0"`
-	TTR      time.Duration `short:"" long:"ttr" description:"TTR for the job." default:"60"`
+	TTR      time.Duration `short:"" long:"ttr" description:"TTR for the job." default:"60s"`
 
 	Command
 }