Fix branch names in github action (release-depot#79)

Also update the Mergify configuration to specify job names.

Author: jpichon

.github/workflows/test.yml

@@ -1,9 +1,9 @@
 name: Run tests
 on:
   push:
-    branches: [ main ]
+    branches: [ master ]
   pull_request:
-    branches: [ main ]
+    branches: [ master ]
 jobs:
     test:
       runs-on: ubuntu-latest

.mergify.yml

@@ -7,5 +7,10 @@ pull_request_rules:
       conditions:
           - label!=no-mergify
           - '#approved-reviews-by>=1'
-          - status-success=Run tests
+          - status-success=Run tests / test (2.7)
+          - status-success=Run tests / test (3.6)
+          - status-success=Run tests / test (3.8)
+          - status-success=Run tests / test (3.9)
+          - status-success=Run tests / flake8
+          - status-success=Run tests / integration
       name: default