remove SWO global import until its utility within AIO is clearer

[turbomam]

SWO is promising for axiomatic links to AIO terms, but it also includes off-topic classes like 'kinase activity' from the Gene Ontology. It also uses a non-standard IRI format, which may be difficult for the ODK to parse.

This PR will remove all traces of SWO until we identify what its value is and what sacrifices or workarounds we are willing to make for the sake of importing all or parts of it.

see also

• restore all or parts of the software ontology (SWO) for inclusion in AIO axioms, once bugs are worked out #83
• What are the GO terms doing here? #63
• unexpected presence of GO terms allysonlister/swo#63