goji/pat became incompatible with bingo


goji/pat became incompatible, as they have updated their API. 

```
github.com/hifx/bingo
/go/pkg/mod/github.com/hifx/bingo@v0.0.0-20170905060144-facde7e3115f/util.go:45:18: 
cannot use ctx (type "context".Context) as type *http.Request in argument to pat.Param
```