patch 8.0.0900: :tab options doesn't open a new tab page

Problem:    :tab options doesn't open a new tab page. (Aviany)
Solution:   Support the :tab modifier. (closes #1960)
diff --git a/src/version.c b/src/version.c
index 707be4f..9e3764e 100644
--- a/src/version.c
+++ b/src/version.c
@@ -770,6 +770,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    900,
+/**/
     899,
 /**/
     898,