Fix pip install command in test workflow and requirements_dev.in

* **.github/workflows/test.yml**
  - Correct pip install command to install both requirements and the local checked out package.

* **requirements_dev.in**
  - Add `-e .` to install the local package in development mode.

.github/workflows/test.yml

@@ -24,7 +24,8 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install -r requirements_dev.txt.txt
+          pip install -r requirements_dev.txt
+          pip install -e .
 
       - name: Run tests
         run: |

requirements_dev.in

@@ -1,2 +1,3 @@
 # Development dependencies
 pytest
+-e .