Initial proposal to differentiate sam only and sat only tests

Now tests can use decorators to run/skip tests basead on server modes:
- runIf('sam') - runs only on sam server
- runIf('sat') - runs only on sat server
- no decoractor - runs on all server modes
Better to use the builtin `skipIf` here:

```python
return unittest.skip(
    project.lower() == mode.lower(),
    'This test will run only on {0} server.'.format(project)
)