Fixed issue with sklearn 0.20

Author: mvargas33

.github/workflows/main.yml

@@ -63,14 +63,6 @@ jobs:
           pip install git+https://github.com/skggm/skggm.git@${SKGGM_VERSION}
           pytest test --cov
           bash <(curl -s https://codecov.io/bash)
-      - name: Run Tests with skggm + scikit-learn 0.20.3
-        env:
-          SKGGM_VERSION: a0ed406586c4364ea3297a658f415e13b5cbdaf8
-        run:  |
-          pip uninstall scikit-learn
-          pip install scikit-learn==0.20.3
-          pytest test --cov
-          bash <(curl -s https://codecov.io/bash)
       - name: Syntax checking with flake8
         run: |
           pip install flake8