Update workflow

Author: MaximLippeveld

.github/workflows/main.yml

@@ -12,6 +12,9 @@ jobs:
         uses: actions/setup-python@v2
         with:
           python-version: ${{ matrix.python-version }}
+      - name: Install SCIP
+        run: |
+          pip install .
       - name: Install dev dependencies
         run: |
           pip install .[dev]