[setup.py] add 'test_suite' to enable `python setup.py test`
[setup.py] add 'test_suite' to enable `python setup.py test`

also, add test *.glif files to package_data, so users can run test modules against the installed cu2qu by doing e.g.:

```
python -m cu2qu.test.pens_test
```

googlefonts/fonttools,fonttools/fonttools,googlei18n/cu2qu,googlefonts/cu2qu