patch 8.1.0608: coverals is not updating

Problem:    Coverals is not updating.
Solution:   Adjust path in Travis config.
diff --git a/src/version.c b/src/version.c
index 9daf4f7..8157365 100644
--- a/src/version.c
+++ b/src/version.c
@@ -800,6 +800,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    608,
+/**/
     607,
 /**/
     606,