Add 0.3 branch to pull request workflow (mathLab#759)

Author: FilippoOlivo

.github/workflows/tester.yml

@@ -5,6 +5,7 @@ on:
     branches:
       - "master"
       - "dev"
+      - "0.3"
 
 jobs:
   unittests: #################################################################
@@ -75,4 +76,4 @@ jobs:
           threshold: 80.123
           fail: true
           publish: true
-          coverage-summary-title: "Code Coverage Summary"
+          coverage-summary-title: "Code Coverage Summary"