Release v1.2.5 - add dry option

This release brings a dry argument to blobconverter - it allows you to get compilation commands which you can use for manual compilation. This can come in handy with large models or offline usage.

You can use this function in two ways:

blobconverter.from_zoo(..., dry=True)  # dry argument is available for any compilation method

or

$ python3 -m blobconverter [...] --dry

These will return compilation commands, similar to the ones below:

[
'/app/venvs/venv2021_4/bin/python /app/model_compiler/openvino_2021.4/downloader.py --precisions FP16 --output_dir /tmp/blobconverter/c712744c08e24f459ab8562f2fc07487 --cache_dir /tmp/modeldownloader/2021_4 --num_attempts 5 --name mobilenet-ssd --model_root /tmp/blobconverter/c712744c08e24f459ab8562f2fc07487', 
'/app/venvs/venv2021_4/bin/python /app/model_compiler/openvino_2021.4/converter.py --precisions FP16 --output_dir /tmp/blobconverter/c712744c08e24f459ab8562f2fc07487 --download_dir /tmp/blobconverter/c712744c08e24f459ab8562f2fc07487 --name mobilenet-ssd --model_root /tmp/blobconverter/c712744c08e24f459ab8562f2fc07487', 
'/opt/intel/openvino/deployment_tools/inference_engine/lib/intel64/myriad_compile -m /tmp/blobconverter/c712744c08e24f459ab8562f2fc07487/mobilenet-ssd/FP16/mobilenet-ssd.xml -o /tmp/blobconverter/c712744c08e24f459ab8562f2fc07487/mobilenet-ssd/FP16/mobilenet-ssd.blob -c /tmp/blobconverter/c712744c08e24f459ab8562f2fc07487/myriad_compile_config.txt -ip U8'
]