stage invalid

when executing 

```
play clean compile stage
```

[error] Not a valid command: stage (similar: last-grep, set, last)
[error] Not a valid project ID: stage
[error] Expected ':' (if selecting a configuration)
[error] Not a valid key: stage (similar: state, target, tags)
[error] stage
[error]      ^

change stage to last get passed.
