Post PHPUnit test results to Gitea

Enable in phpunit.xml with

<phpunit printerClass="JHodges\GiteaBotPHPUnit\ResultPrinter">

<logging>
  <log type="junit" target="/tmp/logfile.xml"/>
  <log type="testdox-html" target="/tmp/testdox.html"/>
  <log type="testdox-text" target="/tmp/testdox.txt"/>
</logging>