SchematicTestRunner.callRule does not use the logger by default

_From @FrozenPandaz on June 6, 2018 3:12_

### Bug Report or Feature Request (mark with an `x`)
```
- [x] bug report -> please search issues before submitting
- [ ] feature request
```

### Area
```
- [x] devkit
- [ ] schematics
```

### Versions

Ubuntu

### Repro steps

```ts

const schematicRunner = new SchematicTestRunner(
collectionName,
pathToCollectionJson
);
const spy = spyOn(schematicRunner.logger, 'info');
schematicRunner
.callRule((host: Tree, context: SchematicContext) => {
context.logger.info('Hello world!');
, Tree.empty())
.subscribe(result => {
expect(spy).toHaveBeenCalledWith('Hello world!');
});
```
### The log given by the failure

Expected spy to have been called 'Hello world!' but was not called.

### Desired functionality

The SchematicTestRunner logger should be used by default and the test should pass

### Mention any other details that might be useful

Any unit tests which test rules

_Copied from original issue: angular/devkit#1016_

Inizia da SchematicTestRunner.callRule e segui come il suo logger viene fornito al contesto della regola. Esamina i test unitari per le regole e riproduci l'esempio mostrato, quindi verifica che il logger del runner riceva “Hello world!” per impostazione predefinita.

Scritto dal modello di indicizzazione a partire dal testo della issue.