Wrote failing test for issue #1

- [x] Write failing test
- [ ] Implement solution

Of note is the fact that we won't have a specific method for 'parsing'
the HTML of the response. It looks like I'll have to consider an HTML
DOM library to parse the code instead.
Merge branch 'master' into feature-discover-from-html-body

Updated the Travis configuration in master and needed to update this in
the feature branch to prevent Travis from reporting failed builds
Implementation to resolve issue #1.

Using jsdom to create a DOM of the request body, if the link is not
available in the link headers, the DOM is created and it now pulls the
link elements and finds any matching WebMention references.
Merge branch 'feature-discover-from-html-body'

Releasing this feature moves the version of lookup-webmention-server to
version 0.1.0