Plain logger should emit a newline

lib/vagrant/util/plain_logger.rb

@@ -5,7 +5,7 @@ module Vagrant
     class PlainLogger < ::Logger
       def format_message(level, time, progname, msg)
         # We do no formatting, its up to the user
-        msg
+        "#{msg}\n"
       end
     end
   end

test/vagrant/util/plain_logger_test.rb

@@ -10,8 +10,8 @@ class PlainLoggerUtilTest < Test::Unit::TestCase
     assert @instance.is_a?(::Logger)
   end
 
-  should "not attempt to format the message in any way" do
+  should "just add a newline to the message" do
     msg = "foo bar baz"
-    assert_equal msg, @instance.format_message("1", "2", "3", msg)
+    assert_equal "#{msg}\n", @instance.format_message("1", "2", "3", msg)
   end
 end