Feature detect based on Ruby version.

I didn't want to do this, FNM_EXTGLOB is defined on 2.1.x, but Dir.glob
returns the wrong value on Ruby less than 2.2.0.  Checking for a
case-insensitive FS seems too hard, so just check Ruby version  Checking
for a case-insensitive FS seems too hard, so just check Ruby version.

actionview/lib/action_view/template/resolver.rb

@@ -196,7 +196,7 @@ module ActionView
       }
     end
 
-    if File.const_defined? :FNM_EXTGLOB
+    if RUBY_VERSION >= '2.2.0'
       def find_template_paths(query)
         Dir[query].reject { |filename|
           File.directory?(filename) ||