chore(travis): add Travis deployment

[terinjokes]

fixes #10.

Would require some additional work before merging:

• [x] enable Travis CI for this repository
• [x] enable the "Build only if .travis.yml is present" option (so Travis CI doesn't attempt to build the master branch)
• [x] setup the GITHUB_TOKEN environment variable in Travis CI (Travis CI docs)

After merging:

• [ ] Checkout the branch as "source" and push
• [ ] Change the Default Branch on GitHub to "source"

Travis CI will pickup that there's now a "source" branch, then build and deploy the site.