Timeout integration tests CI after 1 hour. (#317)

Author: Gnuxie

.github/workflows/mjolnir.yml

@@ -13,6 +13,7 @@ jobs:
   build:
     name: Integration tests
     runs-on: ubuntu-latest
+    timeout-minutes: 60
     steps:
     - uses: actions/checkout@v2
     - name: install mx-tester