Merge pull request #4 from wayofthepie/persistent

Persistent
Create README.md
Update deps for http api

The main riverd module (riverd) had problems building due to
dependencies. Building riverd-http-api pulled in either which pulled in
monad-control 1.0.0.1, riverd needs happstack-server which wants
monad-control <= 0.4 so updating the deps on riverd-http-api to
explicitly pull in 0.3.3.0 allows all packages to be built (luckily
either has bounds on monad-control (>=0.3.2 && <1.1).

The build dependencies need to be updated across the project to prevent
this, perhaps a switch to using stackage would also be beneficial?
Update README.md

Add current working goals
Fix markdown
Merge branch 'master' of https://github.com/wayofthepie/riverd