Merge pull request #3 from railsaholic/avoid_indent_method_redefined_…

…warning

Avoid, method redefined warning for method 'indent'

lib/treetop/ruby_extensions/string.rb

@@ -28,11 +28,13 @@ def tabto(n)
     end
   end
 
-  def indent(n)
-    if n >= 0
-      gsub(/^/, ' ' * n)
-    else
-      gsub(/^ {0,#{-n}}/, "")
+  unless method_defined?(:indent)
+    def indent(n)
+      if n >= 0
+        gsub(/^/, ' ' * n)
+      else
+        gsub(/^ {0,#{-n}}/, "")
+      end
     end
   end