Use streaming for DynamicURLStore's set_data method.
Add 401 to potential Auth errors.
And again in main class.
Merge pull request #88 from enthought/fix/authentication-errors

Fix auth errors
Merge pull request #82 from enthought/fix/url-store-stream-data

Use streaming for DynamicURLStore's set_data method.
Add DynamicURLStore docstring.
Merge pull request #90 from enthought/fix/URLStore-docstrings

Add DynamicURLStore docstring
Merge branch 'master' into feature/DynamicURLStore-delete
Update docs.