Provide a global php.ini precision setting

This is needed, because some actual floating asserts in tests only work correctly with this specific precision of 8. If this setting is not provided, php will rely on the system's provided php.ini precision setting, which than will cause some failures in the tests.

phpunit.xml.dist

@@ -30,4 +30,8 @@
         </whitelist>
     </filter>
 
+    <php>
+        <ini name="precision" value="8"/>
+    </php>
+
 </phpunit>