fix(etcd): get consistent with etcdctl on printing versions

Lets get a bit more consistent in printing the versions:

```
$ ./bin/etcd -version
etcd version 0.3.0+git
$ ./bin/etcdctl -v
etcdctl version 0.3.0+git
```
Merge pull request #565 from philips/cleanup-version

fix(etcd): get consistent with etcdctl on printing versions