Update Postgres Accessibility

## What
Lighthouse can now connect to Postgres in 3 different ways.  Lighthouse now panics if connection to the database fails, because I'm tired of the Lighthouse silently failing.

### Lighthouse Inside Docker
* run database in docker container 
  * `docker run --name postgres-image -d postgres:latest`
  * `docker run -t -i --rm -p 5000:5000 --link postgres-image:postgres lighthouse`

### Lighthouse Outside Docker
* run database on localhost
  * read more [here](http://www.postgresql.org/docs/9.1/static/server-start.html)
  * `$GOPATH/bin/lighthouse`
* run database in docker container 
  * `docker run -p 5432:5432 -d postgres:latest`
  * `$GOPATH/bin/lighthouse`
Yeah, I see what you mean.  It was meant to be more like you can avoid installing it if you're willing to run it in a docker container.