Pangsitpy

- Update `tensorflow` version to `2.2.0`

- Update module `model`
- def `visualize_training`
> Added new argument `colors=('y', 'b')`.

- Update module `model`
- def `visualize_training`
> Updated some scripts
- Update module `scaling`
- def `min_max_scaler`
> Updated conditional `fit_from_data` in `if` statement
- def `standart_scaler`
> Updated conditional `fit_from_data` in `if` statement

- Update `README.md`
- Update module `model`
- def `visualize_training`
> Add label x-axis & y-axis to plot figure

- Update module `model`
- def `visualize_training`
> Update logical process

- Update module `model`
- def `visualize_training`
> Argument `output_file=None` is now disabled, use (`acc_output_file=None`, `loss_output_file=None`) instead.

> Add new argument `metrics=('acc', 'loss')`. Support for keras's metrics.