toRDF() without providing a base IRI doesn't produce phylorefs and phylogenies

[gaurav]

In phyx.js v1.0.1, using new PhyxWrapper({...}).toRDF() without providing a baseIRI on the Brochu 2003 example in Klados (https://github.com/phyloref/klados/blob/5ff43402afdf5a1f53fce3447537e4f92a4f8932/public/examples/brochu_2003.json) doesn't emit phylogenies and phyloreferences for some reason. We appear to have missed this during testing since -- for replicability reasons -- all the tests in this repo use a base IRI.

• Add a test that calls .toRDF() without including a base IRI.
• Figure out why it doesn't emit phylorefs and phylogenies.
• Fix the bug