Add a new CLI command: `linkerd profile --template` which outputs a sample service profile yaml. Users can edit this sample and then `kubectl apply` it to add a service profile. The sample serves as "documentation by example" of what service profiles may contain.
Example usage:
```bash
linkerd profile -n emojivoto --template web-svc > web-svc-profile.yaml
# edit web-svc-profile.yaml in your favorite editor
kubectl apply -f web-svc-profile.yaml
```
Signed-off-by: Alex Leong <alex@buoyant.io>