Added xdebug env varaible.

Author: hexydec

.github/workflows/tests.yml

@@ -16,6 +16,8 @@ jobs:
           php_extensions: mbstring xdebug
           bootstrap: src/autoload.php
           args: --coverage-text --coverage-clover=coverage.xml tests
+          env:
+            XDEBUG_MODE: coverage
 
       - name: Upload coverage to Codecov
         uses: codecov/codecov-action@v1