Change how we install package for CI

.github/workflows/ci.yml

@@ -20,8 +20,9 @@ jobs:
           python-version: '3.9.x'
       - name: Install dependencies
         run: |
-          # python -m pip install --upgrade pip
-          pip install -r requirements.txt
+          python -m pip install --upgrade pip
+          pip install build
+          pip install .[test]
       - name: Compile CBC binary
         run : |
           sudo apt-get install gcc g++ gfortran libgfortran-9-dev liblapack-dev libamd2 libcholmod3 libmetis-dev libsuitesparse-dev libnauty2-dev git