[gnome-nibbles] Use "grey" consistently

[Iulian Radu <iulianradu src gnome org>]

commit 7357fdba860f32643a070e3b04da894f0b114296
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Sun Jun 28 21:51:31 2015 -0500

    Use "grey" consistently
    
    I don't care either way, but I see a runtime warning about a missing
    snake-grey.svg when it is snake-gray.svg.

 data/pix/Makefile.am                        |    2 +-
 data/pix/{snake-gray.svg => snake-grey.svg} |    0
 src/nibbles-view.vala                       |    2 +-
 3 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/data/pix/Makefile.am b/data/pix/Makefile.am
index 86eee3f..68d1459 100644
--- a/data/pix/Makefile.am
+++ b/data/pix/Makefile.am
@@ -14,7 +14,7 @@ SMALL_PIX = \
        snake-blue.svg \
        snake-cyan.svg \
        snake-green.svg \
-       snake-gray.svg \
+       snake-grey.svg \
        snake-magenta.svg \
        snake-red.svg \
        snake-yellow.svg \
diff --git a/data/pix/snake-gray.svg b/data/pix/snake-grey.svg
similarity index 100%
rename from data/pix/snake-gray.svg
rename to data/pix/snake-grey.svg
diff --git a/src/nibbles-view.vala b/src/nibbles-view.vala
index ef2a17f..2057dfd 100644
--- a/src/nibbles-view.vala
+++ b/src/nibbles-view.vala
@@ -51,7 +51,7 @@ public class NibblesView : GtkClutter.Embed
       "yellow",
       "cyan",
       "purple",
-      "gray"
+      "grey"
     };
 
     public NibblesView (NibblesGame game)