IRI expansion with missing `@base` does not conform to RFC 3986 about pyld

[RinkeHoekstra]

I started wondering why the test suite doesn't pick this up, and the explanation is in the runtests.py file:

pyld/tests/runtests.py

Lines 259 to 264 in 316fbc2

	# expand @id and input base
	if 'baseIri' in manifest.data:
	data['@id'] = (
	manifest.data['baseIri'] +
	os.path.basename(str.replace(manifest.filename, '.jsonld', '')) + data['@id'])
	self.base = self.manifest.data['baseIri'] + data['input']

Because the manifest files specify a baseIRI value, the test will always run with a base specified. This means that the situation reported in this issue is not recognised.

Rewriting the test is not an option as with an unspecified base IRI, the output will be application specific.