ScaleComposite should accept scaling parameters on construction

It would be nice to be able to provide scaling parameters when constructing the ScaleComposite rather than at sample-time
```
sampler = ScaleComposite(child, bias_range=(-1, 1))
```
Ideally we would then be able to override this behaviour when calling `.sample`
```
sampler.sample(bqm, bias_range=(-.5, .5))
```