0.2.2 Release

• Include work by @Sinclert on supporting remote JSON schemas.
• New JsonSchemaResolver and HTTPSchemaDownloader objects.
• Don't invalidate an empty errors list in DataFileValidator.
• Check that each value of cmenergies keyword is numeric.
• Allow data_schema and table_doi keys in submission.yaml file.
• Bump native HEPData schema version to 1.0.1 after these changes.
• Improve metadata pushed to PyPI for tagged releases.