Update tool to support folders

Folders are available since Grafana v.5.0.*. Create scripts to migrate
folders and dashboards (with folders id)

Dashboard replacement

A 412 failure from grafana prevents passing a dashboard with a slug that
is already present (i.e. restoring from a backup) to createDashboard.py.
Handle this by always deleting dashboards with the same name from
grafana prior to POSTing the new dashboard.

* Use the PEP 8 recommended whitespace formatting for .py files
* Add intellij files to the .gitignore file patterns

fix typo