Continue working on PR#25 (https://github.com/ysde/grafana-backup-tool/pull/25):
* move all python into src/
* delete boilerplate restore_SOMETHING.sh scripts
* update README.md
* add some things to .gitignore

1.Make it python2 and python3 compatible 2.Try to solve special character when saving dashboard, folder problem 3.Add more verbose log message

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