CI: removed unit test timeout (#23)

Author: peter0083

.github/workflows/continuous-integration.yml

@@ -13,7 +13,6 @@ jobs:
   test:
     name: Unit tests 
     runs-on: ubuntu-latest
-    timeout-minutes: 10
     strategy:
       matrix: # matrix testing strategy
         python-version: ['3.7', '3.8', '3.9', '3.10']