support arch package dump for ci reports

Author: thelamer

ci/ci.py

@@ -208,6 +208,8 @@ def endtest(container,report_tests,report_containers,report_status,tag,build_ver
         command = 'apt list'
     elif base == 'fedora':
         command = 'rpm -qa'
+    elif base == 'arch':
+        command = 'pacman -Q'
     try:
         info = container.exec_run(command)
         packages = info[1].decode("utf-8")