Remove add_table test because it's very slow and tends to fail

https://github.com/2ndQuadrant/pglogical/issues/126

--- a/Makefile
+++ b/Makefile
@@ -57,7 +57,7 @@
 SCRIPTS_built = pglogical_create_subscriber
 
 REGRESS = preseed infofuncs init_fail init preseed_check basic extended conflict_secondary_unique \
-		  toasted replication_set add_table matview bidirectional primary_key \
+		  toasted replication_set matview bidirectional primary_key \
 		  interfaces foreign_key functions copy sequence triggers parallel row_filter \
 		  row_filter_sampling att_list column_filter apply_delay multiple_upstreams \
 		  node_origin_cascade drop
