Examples:
    You can run a single test by appending a line number to a filename:

        <%= executable %> test/models/user_test.rb:27

    You can run multiple tests with in a line range by appending the line range to a filename:

        <%= executable %> test/models/user_test.rb:10-20

    You can run multiple files and directories at the same time:

        <%= executable %> test/controllers test/integration/login_test.rb

    By default test failures and errors are reported inline during a run.