patch 8.1.0188: no test for ":cscope add"

Problem:    No test for ":cscope add".
Solution:   Add a test. (Dominique Pelle, closes #3212)
diff --git a/src/version.c b/src/version.c
index 559d8be..892b9ae 100644
--- a/src/version.c
+++ b/src/version.c
@@ -790,6 +790,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    188,
+/**/
     187,
 /**/
     186,