test/unit.rb: color on tty

* test/lib/test/unit.rb (Test::Unit::StatusLine#_prepare_run):
  colorize by default on tty.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53197 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/lib/test/unit.rb

@@ -565,7 +565,7 @@ module Test
         when :always
           color = true
         when :auto, nil
-          color = @options[:job_status] == :replace && /dumb/ !~ ENV["TERM"]
+          color = (@tty || @options[:job_status] == :replace) && /dumb/ !~ ENV["TERM"]
         else
           color = false
         end