Add in new query class called Querist

http://www.oxforddictionaries.com/definition/english/querist
Add request promise

- wrap up general request logic in request-promise
- add in chai-as-promised to check our promises
Add require-subvert

Allows us to mock dependencies that are required on a function that is exported on a module.
Add lots of tests for request-promise
Fixed up testing for querist

Use require-subvert to test the exported function
Updated look of test to make it a little more readable
set node_env inside to fix build issues
q
Merge pull request #14 from alphagov/datasets

Adding query class
Change the way we write node env into travis

- Cf. https://gist.github.com/zpratt/9176787#file-travis-yml
Merge pull request #15 from alphagov/travisenv

Change the way we write node env into travis
Refactored sendEmail to send

Updated the tests
Send email for out-of-date data-sets

Call the data-sets endpoint and send an emai with the results.
Merge pull request #16 from alphagov/datasets

email for out-of-data data-sets
Introduced log levels

This allows us to do things like:

```
log.request('this is a request');
log.email('ohh were sending an email');
```
Update querist get to take options

allows us to use a bearer token

Update request-promise to pass the options through to request
Adding moment package
Get the out of date data sets

Then get the emails for those data sets

Then email the people!
Slightly less loggy email logging
Change request-promise and querist to just require url/options

- simplifies calls, but still allows a baseUrl to be added in where it makes sense