[Feature Request] TensorBoardOutputConfig local output path

Hi, I really wish I could use `TensorBoardOutputConfig` when my SageMaker Estimator instance type is `local` or `local_gpu`.

This could be accomplished by either or both of:
- Enabling streaming to s3 when running local mode jobs
- Enabling a local output path instead of an s3 output path, for example:

```python
from sagemaker.debugger import TensorBoardOutputConfig

instance_type = 'local_gpu'

tb_output_path = "file:///local/path/to/stream/tensorboard/files/to"

tensorboard_output_config = TensorBoardOutputConfig(
# and rename s3_output_path to output_path?
output_path=tb_output_path,
container_local_output_path='/tensorboard'
)
```
This would make it possible to perform local debugging of tensorboard logging code within my sagemaker scripts. Without local debugging, writing tensorboard logging code for sagemaker jobs can be a very slow process.

Start with TensorBoardOutputConfig and the local and local_gpu Estimator modes described in the issue. Determine whether the change should support streaming to S3, a file:// output path, or both, then verify that local debugging of TensorBoard logging works as requested.

Written by the indexing model from the issue text.