update readme

Author: mquadrana

README.md

@@ -38,10 +38,13 @@ You can do it in your main python environment (necessarily in the `srs` env), a
 Anaconda users should already have Jupyter Notebook installed, so they can skip this step.
 
 5. Then activate the environment with `source activate srs` or `conda activate srs`, and install a new `iptyhon` kernel by running:
-
  ```bash
  python -m ipykernel install --name srs
  ``` 
+ If you get "Permission denied" error with the above command, try with
+ ```bash
+ python -m ipykernel install --name srs --user
+ ``` 
 
 6. Finally, launch the Jupyter Notebook with
  ```bash