Add Netlify logo to home page

**User Story**
As a Free Code Camp user
I want to know that Netlify was used to deploy the Free Code Camp website
So that the development community knows how we continuously automatically deliver awesomeness

**Acceptance Criteria**
GIVEN I am a Free Code Camp User
WHEN I navigate to the Free Code Camp Columbus home page
THEN I will see the "Built with Netlify" logo centered on the bottom of the page

GIVEN I am a Free Code Camp User
WHEN I click the "Built with Netlify" logo
THEN a new tab will open
AND the new tab will show the contents of the [Netlify link](https://www.netlify.com)

_Additional information_

- The Netlify logo needs to be visible and clickable on the home page so we can retain our Netlify pro features. This existed in a previous iteration and was lost somewhere
- [Here is the original GitHub issue](https://github.com/FCCColumbus/cbus-web/issues/18)
- [Here is the commit with the code that was added to app.js](https://github.com/FCCColumbus/cbus-web/pull/23/commits/d49acfa8ed04bbf6eaae0b122d328942a3de02f1#diff-3d74dddefb6e35fbffe3c76ec0712d5c416352d9449e2fcc8210a9dee57dff67)