config: suites_dir and scenarios_dir are now a list of paths

This allows inheriting suites or scenarios from eg. sysmocom/ dir, while
still allowing to apply new suites and scenarios on top.

Change-Id: Icecdae32d400a6b6da2ebf167c1c795f7a74ae96
diff --git a/selftest/resource_test/resource_test.ok b/selftest/resource_test/resource_test.ok
index 0ad760e..91acaaf 100644
--- a/selftest/resource_test/resource_test.ok
+++ b/selftest/resource_test/resource_test.ok
@@ -14,9 +14,9 @@
 {'default_suites_conf_path': '[PATH]/selftest/resource_test/conf/default-suites.conf',
  'defaults_conf_path': '[PATH]/selftest/resource_test/conf/defaults.conf',
  'resource_conf_path': '[PATH]/selftest/resource_test/conf/resources.conf',
- 'scenarios_dir': '[PATH]/selftest/resource_test/conf/scenarios',
+ 'scenarios_dir': ['[PATH]/selftest/resource_test/conf/scenarios'],
  'state_dir': '[PATH]/selftest/resource_test/conf/test_work/state_dir',
- 'suites_dir': '[PATH]/selftest/resource_test/conf/suite_test',
+ 'suites_dir': ['[PATH]/selftest/resource_test/conf/suite_test'],
  'trial_dir': '[PATH]/selftest/resource_test/conf/trial'}
 *** all resources:
 {'arfcn': [{'_hash': 'e620569450f8259b3f0212ec19c285dd07df063c',