Add cfs fcbf #39 (#40)

* Implement CFS/FCBF in splitter

* Split Splitter class to its own file
Update hyperparams table in docs
Implement CFS/FCBS with max_features and variable type

* Set mfs to continuous variables

* Fix some tests and style issues in Splitter

* Update requirements in github CI

.github/workflows/main.yml

@@ -26,6 +26,7 @@ jobs:
           pip install -q --upgrade pip
           pip install -q -r requirements.txt
           pip install -q --upgrade codecov coverage black flake8 codacy-coverage
+          pip install -q git+https://github.com/doctorado-ml/mfs
       - name: Lint
         run: |
           black --check --diff stree