phborba/pytorch_segmentation_models_trainer: Version 0.2.0

New custom callbacks: ImageSegmentationResultCallback: Callback that logs the results of the training on TensorBoard and on saved files; and WarmupCallback: Applies freeze weight on encoder during callback epochs and then unfreezes the weights after the warmup epochs. Metrics added to Segmentation Model: Accuracy; Precision; Recall; and Jaccard Index (IoU)