Merge branch '3.4' into 4.0

* 3.4:
  [HttpKernel] reset kernel start time on reboot
  Add code of Conduct links in our README
  [DI] never inline lazy services
  bumped Symfony version to 3.4.12
  updated VERSION for 3.4.11
  updated CHANGELOG for 3.4.11
  Default testsuite to latest PHPUnit 6.*
  [Github] Update the pull-request template
  bumped Symfony version to 2.8.42
  updated VERSION for 2.8.41
  updated CHANGELOG for 2.8.41
  [HttpFoundation] Fix cookie test with xdebug
  [Serializer] Check the value of enable_max_depth if defined
  [DI] remove dead code
  [PhpUnitBridge] silence some stderr outputs
  [Validator] Update sl translation

Author: nicolas-grekas

Resources/translations/validators.sl.xlf

@@ -314,6 +314,10 @@
                 <source>This is not a valid Business Identifier Code (BIC).</source>
                 <target>To ni veljavna identifikacijska koda podjetja (BIC).</target>
             </trans-unit>
+            <trans-unit id="82">
+                <source>Error</source>
+                <target>Napaka</target>
+            </trans-unit>
         </body>
     </file>
 </xliff>