Add Midas info to README

From our one-pager about midas, put it in the repo too.

First commit for this repo at 18F.
Update TravisCI link

To 18F
Update link to 18F
initial OSX instructions, add git submodule stuff
more concise git submodule command, per @polastre suggestion
update config file section so demo will run, and make clear that editing config files isn’t needed for the demo to run
syntax fixes to allow copy/paste of sql commands
Merge pull request #191 from ultrasaurus/install-improve-devel

install on osx, plus git submodule command