Add tests from develop

Added tests from develop. The test results need to be modified for 2.0.

maxscale-system-test/cache/cache_basic/t/select2.test

@@ -0,0 +1,11 @@
+#
+# Cache basic
+#
+# See ../cache_rules.
+#
+# This script assumes t/update2.test has been successfully executed.
+#
+
+USE cachingdb;
+
+SELECT * FROM caching;