Update regression tests

sql/repmgr_extension.sql

@@ -1 +1,25 @@
+-- minimal SQL tests
+--
+-- comprehensive tests will require a working replication cluster
+-- set up using the "repmgr" binary and with "repmgrd" running
+
+-- extension
 CREATE EXTENSION repmgr;
+
+-- tables
+SELECT * FROM repmgr.nodes;
+SELECT * FROM repmgr.events;
+SELECT * FROM repmgr.monitoring_history;
+
+-- views
+
+SELECT * FROM repmgr.replication_status;
+SELECT * FROM repmgr.show_nodes;
+
+-- functions
+SELECT repmgr.get_new_primary();
+SELECT repmgr.get_voting_status();
+SELECT repmgr.reset_voting_status();
+SELECT repmgr.standby_get_last_updated();
+SELECT repmgr.standby_set_last_updated();
+SELECT repmgr.unset_bdr_failover_handler();