MAPG-94 save test results and save only the result xml as artifact

.gitignore

@@ -1,3 +1,4 @@
 .env
 installed
+unit_test_results.xml
 vendor

bitbucket-pipelines.yml

@@ -7,9 +7,9 @@ pipelines:
               caches:
                   - composer
               artifacts:
-                  - vendor/**
+                  - unit_test_results.xml
               script:
                   - apt-get update && apt-get install -y unzip
                   - curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
                   - composer install
-                  - vendor/bin/phpunit --testdox tests
+                  - vendor/bin/phpunit --log-junit unit_test_results.xml --testdox tests