Deeponto

Hot-fix to the `openprompt` dependency issue by setting it as optional.

**Full Changelog**: https://krr-oxford.github.io/DeepOnto/changelog/

This release mainly introduces `deeponto.onto.taxonomy` to support graph-based deep learning models. It also incorporates some incremental improvements, such as the new verbalisation support and logging slience for ELK reasoner (relevant to issue 13).

This release concerns a major update of the ontology processing modules especially **reasoning** (e.g., adding in ELK reasoner) and **verbalisation** (e.g., adding in support of various axioms and property chain), and also makes the OAEI evaluation ready.

The Java library is manually edited where the `jar` files related to `elk-0.4.3` were removed because this version does not support entailment, etc. The latest version `elk-0.5.0` was manually added.

This update includes several minor changes (argument, naming, etc.) of certain methods and makes all utility methods able to be directly imported from `deeponto.utils` instead of being static methods.

Deploy OAEI utilities and create a sub-repository [OAEI-Bio-ML](https://github.com/KRR-Oxford/OAEI-Bio-ML) for the OAEI-related scripts. Fixing bugs mentioned in issue #10.