Merge invenio-scripts into B2SHARE

This request will merge https://github.com/EUDAT-B2SHARE/invenio-scripts into the B2SHARE repository #451. README.md and Installation wiki (https://github.com/EUDAT-B2SHARE/b2share/wiki/Installation) updated accordingly. VM file sync is changed to rsync (#464), and VM memory size set to 1024mb.