Adding upload to S3 with Travis deploy

[andycastleuk]

What does this PR do? (please provide any background)

Enables deploying of the UIToolkit to an S3 bucket.

What tests does this PR have?

N/A

How can this be tested?

The first step is to get this merged. The CI should still function as normal, however when making a change to the package.json file. It should trigger a deploy (which won't actually do anything yet!).

What gif best describes how you feel about this work?

---

• [X] I have checked our general contributing document and the project specific contributing document (if present) and I'm happy for this to be reviewed.

  Reviewers

Review 1

• [x] :+1:

Review 2 *

• [x] :+1:

Review 3 (optional)

• [ ] :+1:

By adding a +1 you are confirming you have...

• Witnessed the work behaving as expected (this could be on the author's machine or screencast).
• Checked for coding anti-patterns.
• Checked for appropriate test coverage.
• Checked all the tests are passing.

* for HX this review must be completed by an SE, SA or Project Guru

[Joezo]

:+1: looks like it should work :)

[hx-markterry]

taken

[hx-markterry]

looking good, only one tiny comment, +1 if that gets fixed.