Areas of improvement

• Readability improvements.
• A bug fix for pretrained_initializer with the latest NumPy.
• Unit tests / CI improvements.
• Addition of evaluation codes for all imagenet models (see #49).

API changes

• Add logits to access a logits tensor directly.
• Add middles() which is equivalent to get_middles().
• Add outputs() which is equivalent to get_outputs().
• Add weights() which is equivalent to get_weights().
• Add summary() which is equivalent to print_summary().

Breaking changes

None.