Fix up formasaurus dependency

[mehaase]

Formasaurus has a strange setup where the dependencies are hidden behind a package extras flag. We are depending on formasaurus 0.9.0, which is not on PyPI yet, so we need to install from S3, but installing over HTTP doesn't support extras flags. So I've temporarily added formasaurus's dependencies as direct dependencies of this project:

Pipfile:

scikit-learn = ">=0.18"
scipy = "*"
sklearn-crfsuite = ">=0.3.1"
joblib = "*"