* common.mk (help): Fix environment variable name and argument.
  Actually it can also be a directory or any argument for
  test/unit runner. [Fixes GH-363]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42091 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2013-07-21

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42092 b2dd03c8-39d4-4d8f-98ff-823fe69b080e