Refactors api modules to enable use of app configs

![Prototype all the things](http://i.imgur.com/KpFjWaz.jpg)

#### What's this PR do?
This patch does the following:
* Moves all configurations into the central config directory
* Refactors api modules as objects to make it easier to pass in the express app object

#### Where should the reviewer start?
The api modules.  I refactored each wrapping them in objects and added each method to its prototype.  You can see the new implementations in `app/router.js`

#### How should this be manually tested?
* Confirm that the new config files are being loaded
* Confirm that I did not miss anything in the refactor.  I am sure I missed something

Hopefully I did not blow everything up

#### What are the relevant tickets?

Closes #44

Thoughts on the capitalization happening here? I like keeping only class names capitalized and variable names lowercased. So what if we did something like this:
```
var Babysitter = require('../pregnancytext/babysitter-api');
var babysitter = new Babysitter(app);
```