Changed Detection boxes and updated file caching

Changed nnio.DetectionBox class:

• Attributes are now named x_min, y_min, x_max, y_max
• x_min and x_max are for width axis and y_min, y_max are for height axis, like in PASCAL VOC.

Changed file caching. Now files from different urls will not conflict when they have the same name.

Added person-reid model

New models for person re-identification:

• nnio.zoo.onnx.reid.OSNet
• nnio.zoo.openvino.reid.OSNet
• nnio.zoo.edgetpu.reid.OSNet

New class: nnio.utils.HumanDataBase for using with person re-id models.

Made Segmentation model lighter

nnio.zoo.edgetpu.DeepLabV3 model is now the light version.

Small changes for comfortable usage

• Now python's auto completion will not show non-relevant imports, especially for nnio.zoo
• Cache is now saved in /home/user/.cache/nnio/0.2/. Earlier it was saved to .../nnio/0.2.1/. Now small updates will not affect saved models.
• Added __eq__ operator for nnio.Preprocessing.

Convenient device naming and myriad's temperature measuring

More convenient device naming

• Names for all devices are written in the same form:
  CPU, GPU, MYRIAD, TPU
• When multiple myriads or TPU's are available, user can choose between them as:
  MYRIAD:0, MYRIAD:1, TPU:0, TPU:1, ...

Measuring myriad temperature

• Temperature will be returned from the model call if return_info flag is used:
  output, info = model(image_prepared, return_info=True)
• Temperature of each myriad can be logged to /home/$USER/.telemetry after each model call.
  To enable this:
  nnio.utils.enable_logging_temperature(True)

Added support for openvino models

New ready models:

• nnio.zoo.edgetpu.segmentation.DeepLabV3
• nnio.zoo.onnx.classification.MobileNetV2
• nnio.zoo.openvino.detection.SSDMobileNetV2

Stable version with few models

Backends available:

• nnio.EdgeTPUModel
• nnio.OpenVINOModel
• nnio.ONNXModel

Ready models available:

• nnio.zoo.edgetpu.classification.MobileNet
• nnio.zoo.edgetpu.detection.SSDMobileNet
• nnio.zoo.edgetpu.detection.SSDMobileNetFace
• nnio.zoo.onnx.detection.SSDMobileNetV1