Use statics for mongoose methods where needed

[alexf4]

We should be able to use static methods to search through all documents of a schema.

[alexf4]

http://stackoverflow.com/questions/29664499/mongoose-static-methods-vs-instance-methods

http://stackoverflow.com/questions/23425303/what-is-the-difference-between-methods-and-statics-in-mongoose

http://stackoverflow.com/questions/19720043/node-js-mongoose-static-method-example