You need to login first: 'scw login' with ~/.scwrc

- When I want to use scalway-cli in docker, I have an error
  **You need to login first: 'scw login'**
- I have a good **.scwrc** and my scaleway/cli version is:

```
docker run -it --rm --volume=$HOME/.scwrc:/root/.scwrc scaleway/cli version
Client version: v1.3.0
Go version (client): go1.4.2
Git commit (client): 199fd8fbaaaaf41a1b8d733e60c054c667f44006
OS/Arch (client): linux/386
```
