Making changes to the underlying model

Steps

Edit tests/input/meta.yaml, tests/input/includes/types.yaml and/or tests/input/includes/mappings.yaml. Be sure to update the version # if the changes are significant using SemVer rules.
1. Run tests/test-base/test_python.py. Verify that the generated python in tests/output/meta.py, tests/output/includes/types.py and/or tests/output/includes/mappings.pyreflects the changes.
2. Run all unit tests in tests/test_base. Make sure that all output file changes are what is expected.
Copy tests/input/meta.py to the biolinkml directory. Copy any other changes to the root directory, including changes in includes.
```
 > cd tests
 > ./newmodel.sh
```
NOTE: Double check that tests/init.py SKIP_MARKDOWN_VALIDATION is False 2) Edit biolinkml/meta.py and set the version number to the same as in the yaml file
Run ALL unit tests.
Note that an unexpected source of testing errors is tests/test_scripts/test_gen_jsonld/GenGSONLDTestCase.#67