Add no-index meta tag to alpha/sponship page

## Context
To avoid the test page being indexed we should add a no-index flag.

This can be done by adding the meta tag to the page: `<meta name="robots" content="noindex">`

## Current Behavior

Indexed as a normal page. 

## Screenshot
The page can be seen here: https://www.codu.co/alpha/sponsorship
