BmiClientSingularity should use own logger

It uses global logging at https://github.com/eWaterCycle/grpc4bmi/blob/1882d5f80c6a471a6eba5f2cd34f9a2fc896d6d7/grpc4bmi/bmi_client_singularity.py#L222

I should be using a local logger with
```
import logging
logger = logging.getLogger(__name__)
...
logger.info('Running /....sif singularity container on port 41749')
```

Then its message can be silenced selectively.