Merge pull request #38 from rodrigo-arenas/0.6.Xdev

O.S matrix test

.github/workflows/ci-tests.yml

@@ -5,10 +5,11 @@ on: [push, pull_request]
 jobs:
   build:
 
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
     strategy:
       matrix:
         python-version: [ 3.7, 3.8, 3.9]
+        os: [ubuntu-latest, windows-latest, macOS-latest]
 
     steps:
       - uses: actions/checkout@v2
@@ -20,7 +21,7 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install pytest
-          if [ -f dev-requirements.txt ]; then pip install -r dev-requirements.txt; fi
+          pip install -r dev-requirements.txt
       - name: Test with pytest
         run: |
           pytest sklearn_genetic/ --verbose --color=yes --assert=plain --cov-fail-under=95 --cov-config=.coveragerc --cov=./ -p no:warnings