Use os.path.join instead of urllib.parse.urljoin, fixes #12
Only use os.path.join for local files
Merge pull request #13 from jhamrick/os-path-join

Use os.path.join instead of urllib.parse.urljoin, fixes #12
Add setter for name property
Add datapackage version property
Add some basic tests
Handle cases where name or datapackage_version are empty/missing
Add license/licenses properties
Add functionality to set licenses
Add getters and setters for the other various properties
Add test for web url
Remove unused imports
Make parameter documentation more consistent
Add docstring to verify_semantic_version