Path in example is wrong

Dear all,
the path in the following example is wrong 
https://github.com/python-accelerator-middle-layer/pyaml/blob/dc967889da30b74f7ec1992b88080ae859418714/examples/ESRF_tune_example/esrf_tune_example.py#L9

It should be 
```python
sr: Accelerator = Accelerator.load("../../tests/config/EBSTune.yaml")
```