In the U.S.,&nbsp;Avon ladies&nbsp;helped pioneer the door-to-door sales business model while peddling makeup and perfumes. Today, one at a time, women are fanning out to reach some of the world&amp;#8217;s most remote markets with desperately needed goods and services.&nbsp;How a&nbsp;traveling salesforce of women could bridge Africa&amp;#8217;s &amp;#8220;last mile.&amp;#8221;