[WIP] Add github actions to run test and publish to pypi

[alejgh]

I have updated 3 GitHub actions files to run automatically the following tasks:

• Run tests and update dependencies on push to master.
• Run tests on pull requests.
• Publish the library to PyPi when a tag is pushed to master.

These actions are based on the ones from biolinkml with some minor modifications.

We still need to create a token with PyPi and write it to the secret keys of this repo.

Also, some of the tests are currently failing. For example, the test_fhir.py test in test_issues uses a turtle file (http://build.fhir.org/observation-example-haplotype2.ttl) which is not found on the server. There are some other tests that we need to take a look into.

[alejgh]

I have fixed some of the tests that were failing:

• Skips were added to the tests relying on the mannheim drugbank sparql endpoint, since it is currently down.
• Updated ttl urls to the fhir examples.
• Updated cli help file.
• Update json-ld text used in the schemaorg tests.

Now just two tests from the ShEx test manifest should be failing.

[alejgh]

I have made some changes and now the n3 mapper test files are created before running the tests. Currently 3 tests are failing related to the shextest manifest, since a couple of tests from the manifest are failing. However, the actions are now ready to go.

Tests will now be run on new pushes to master and pull requests.