Move expired-authz-purger2 config to test directory (#5352)

- Edit integration test to start expired-authz-purger2 with config/
  config-next
- Move config from `cmd/expired-authz-purger2/config.json` to
  `test/config/expired-authz-purger2.json`
- Add a copy of `test/config/expired-authz-purger2.json` to
  `test/config-next/`

Fixes #5351

test/config/expired-authz-purger2.json

@@ -0,0 +1,14 @@
+{
+    "expiredAuthzPurger2": {
+        "syslog": {
+          "stdoutLevel": 6
+        },
+        "db": {
+          "dbConnectFile": "test/secrets/purger_dburl",
+          "maxOpenConns": 10
+        },
+        "gracePeriod": "168h",
+        "batchSize": 1000,
+        "debugAddr": ":8015"
+    }
+}

test/integration-test.py

@@ -58,7 +58,7 @@ def run_expired_authz_purger():
         tool = "expired-authz-purger2"
         out = get_future_output([
             "./bin/expired-authz-purger2", "--single-run",
-            "--config", "cmd/expired-authz-purger2/config.json"], target_time)
+            "--config", "%s/expired-authz-purger2.json" % (config_dir)], target_time)
         if 'via FAKECLOCK' not in out:
             raise(Exception("%s was not built with `integration` build tag" % (tool)))
         if num is None: