fix bug from last PR

Merge pull request #6 from tingjhenjiang/patch-2

Update labelencoder.py

Merge pull request #5 from tingjhenjiang/patch-1

Upadate labelencoder.py

update documentation with new loss

fix bugs in NLL loss function

first attempt at the negative log likelihood loss

add a squeeze on the weights to deal with shape differences

adding in sample_weights to metrics

Update installation.md

Update README.md

Update setup.cfg

Update version.py

Update CHANGELOG.md