Mark Go plugin as stable

package.json

@@ -96,7 +96,7 @@
         "c9.ide.immediate": "#0b0ee744f9",
         "c9.ide.installer": "#2921efaf6d",
         "c9.ide.language.python": "#ec0b9070a4",
-        "c9.ide.language.go": "#6ce1c7a7ef",
+        "c9.ide.language.go": "#287f090628",
         "c9.ide.navigate": "#5d5707058c",
         "c9.ide.newresource": "#981a408a7b",
         "c9.ide.openfiles": "#2ae85a9e33",