Also had to update the test fixtures because mkdocs, bootstrap, whatever it may be have changed, so the sites end up slightly different.
Reviewed-on: #24
Co-authored-by: Glen Whitney <glen@studioinfinity.org>
Co-committed-by: Glen Whitney <glen@studioinfinity.org>
That is to say, the destination will now be interpreted as an entire
path relative to the source, not simply a filename in the same directory
as the source.
Resolves#20.
