Fix Patreon's backer name (vuejs#3069)

Ian Walter · phanan · commit 50b79bbb190d · 2016-06-13T22:55:46.000+08:00
diff --git a/backers.md b/backers.md
@@ -109,7 +109,7 @@ It could be you!
 - Yegor Sytnyk
 - Guido H.
 - Joan Cejudo
-- Walter
+- Ian Walter
 - Nokola Trifunovic
 - Nicolas Mutis Mesa
 - Fahed Toumi
