Added medication details to the cow.js model

Allows data relating to a specific medication path on a cow to be
stored, for example the dose used.

medication_details = {
        medicine_id: String,
        date_administered: Date,
        dose: String,
        period: **Duration
    }
Updates to models.

The cow route will not render a single cow. Need to look into why,
these additions were an attempt to solve.
Fixed the single cow route
Added /cattle/medicated route

Displays all medicated animals on record
Added route /cattle/pregnant

This route will provide a list of all pregnant cattle to the user
Added /cattle/pregnant to file routes/pregnant.js
Updates to cattle.hbs and cow.hbs

Changed the way that dynamic data is displayed. Now making use of the
{{#with}} handlebars helper.
Began to edit the cattle.hbs view. I am incorporating the edit and data
view into one page.
Updated cattle.hbs

cattle.hbs now has an attractive layout to display cow data. Data is
displayed in a tabulated view and the header is set dynamically
depending on the page being rendered. The header is set using
{{page_title}} which is sent from the server.
Updated some helper text
Updated the medicines.hbs view and layout
Alterations to the cow.hbs styling.

Forms are now displayed in a block fashion, one after the other. Each
form simply has a thin border around it.
Added /cattle/add route

This route will render a form that allows a user to add a new cow. The
add cow form has been removed from the dashboard.
Added a new medicine/add route

This route provides users with a dedicated page to add medicines.
Added a chart to the dashboard in order to preview.

The idea is to eventually provide users with graphical representations
of their monthly pregnancy and medication data.
Added 'add cow' and 'add medicine' buttons
Altered a class in the cow.hbs file
Added 'read' boolean option to the notification system
Updated TODO list as well as added validation to one input field
Added agenda, a scheduling dependency

Allows tasks to be scheduled. This will allow for checking of
notifications.