Bump version: 1.5.2 → 1.6.0

Merge pull request chemprop#338 from davidegraff/refactor/featurizer-…

…mixins

refactor `featurizers` module

Bump version: 1.5.1 → 1.5.2

Bump version: 1.5.0 → 1.5.1

Bump version: 1.4.1 → 1.5.0

Increment version number from v1.4.0 to v1.4.1

Merge pull request chemprop#209 from chemprop/increment_version_140

Update version number for new release 1.4.0

Merge pull request chemprop#194 from chemprop/1.3.1_increment

Increment Version Number

Increment version number to 1.3.0

Incrementing version from 1.1.0 to 1.2.0