v1.13.1

• Datasets are now listed in main according to the number of feature models they have.
• Statistics performance has been improved. They are now stored as counters instead of dynamically counting each table.
• Added publication of the uvl paper (David Benavides et al)
• Minor bug fixes
• Several services and repositories have been refactored.

Full Changelog: v1.13...v1.13.1