Adding mongoDB for Travis.
Adding mongoDB for Travis.

Refer to: http://about.travis-ci.org/blog/august-2012-upcoming-ci-environment-updates/

nickpellant/aasm,pskrz/aasm,artofhuman/aasm,allspiritseve/aasm,Aryk/aasm,ASnow/aasm,HoyaBoya/aasm,aasm/aasm,intfrr/aasm,Funfun/aasm,joshsoftware/aasm,hspazio/aasm,awsmsrc/aasm,oswaldoferreira/aasm,xieyunzi/aasm,reidmorrison/aasm,luxola/aasm,bilby91/aasm,yui-knk/aasm