fix setting setting `space` without setting `rules` in package.json
fix setting setting `space` without setting `rules` in package.json

fixes #5

joakimbeng/xo,jamestalmage/xo,frozzare/xo,markogresak/xo,nelix/xo,floatdrop/xo,ceejbot/xo,RichardLitt/xo,sindresorhus/xo,kidaa/xo,genexp/xo