update doctest.yml to install control

Author: murrayrm

.github/workflows/doctest.yml

@@ -27,8 +27,12 @@ jobs:
     - name: Install full dependencies
       shell: bash -l {0}
       run: |
-        mamba install cvxopt pandas slycot 
+        mamba install cvxopt pandas slycot
 
+    - name: Install python-control from source
+      run: |
+        conda run -n doctest-env pip install .
+	
     - name: Run doctest
       shell: bash -l {0}
       working-directory: doc