Add private repository authentication

Author: jerowork

.github/workflows/test.yaml

@@ -22,6 +22,16 @@ jobs:
         with:
           php-version: ${{ matrix.php-version }}
           tools: composer
+        env:
+          COMPOSER_AUTH_JSON: |
+            {
+              "http-basic": {
+                "jerowork.repo.repman.io": {
+                  "username": "${{ secrets.REPMAN_USERNAME }}",
+                  "password": "${{ secrets.REPMAN_PASSWORD }}"
+                }
+              }
+            }
 
       - name: Install composer dependencies
         run: composer install --prefer-dist --no-progress