patch 8.1.0316: swapinfo() test fails on Travis

Problem:    swapinfo() test fails on Travis.
Solution:   Handle a long host name. (Ozaki Kiichi, closes #3361)
            Also make the version check flexible. (James McCoy)

src/version.c

@@ -794,6 +794,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    316,
 /**/
     315,
 /**/