Add PHPUnit 6.5.x for PHP < 7.2

Author: thelovekesh

.github/workflows/build-test-measure.yml

@@ -532,7 +532,10 @@ jobs:
       - name: Update PHPUnit
         if: needs.pre-run.outputs.changed-php-count > 0
         run: |
-          if [[ $PHP_VERSION == "7.1" ]]; then
+          if [[ $PHP_VERSION == "7.0" ]]; then
+            echo "Installing PHPUnit 6.5.x"
+            composer require --ignore-platform-reqs --no-interaction --no-scripts phpunit/phpunit:^6.5 --with-dependencies
+          elif [[ $PHP_VERSION == "7.1" ]]; then
             echo "Installing PHPUnit 7.5.x"
             composer require --ignore-platform-reqs --no-interaction --no-scripts phpunit/phpunit:^7.5 --with-dependencies
           elif [[ $PHP_VERSION == "7.2" ]]; then