class Autotest::Rspec2

def make_test_cmd(files_to_test)

Overrides Autotest's implementation to generate the rspec command to run 
def make_test_cmd(files_to_test)
  files_to_test.empty? ? '' :
    "#{prefix}#{ruby}#{suffix} -S '#{RSPEC_EXECUTABLE}' --tty #{normalize(files_to_test).keys.flatten.map { |f| "'#{f}'"}.join(' ')}"
end