move dev requirements to file + add pytest for python 3.10

Author: ValentinFrancois

.github/workflows/validate.yml

@@ -25,7 +25,7 @@ jobs:
     - name: install dependencies
       run: |
         python -m pip install --upgrade pip
-        python -m pip install flake8 nose coverage
+        python -m pip install -r requirements_dev.txt
         pip install -r requirements.txt
     - name: lint
       run: |

requirements_dev.txt

@@ -0,0 +1,4 @@
+flake8
+nose
+coverage
+pytest