New test: Check if term README is consistent with owl file

New test to check that the README file in the `terms` sub-directory ([current README preview](https://github.com/incf-nidash/nidm/tree/master/nidm/nidm-results/terms)) is consistent with the definitions in `terms/nidm-results.owl`.

Insure consistency between the term README file (displaying terms and definition sorted by curation status) and the definitions in the owl file.