3.0.0

• PHP >=7.1 required.
• Cluster index is now lazy loaded. If you use iterator methods directly to iterate through all database,
  you must call rewind first.
• Factory now creates database instances but not store them, so next call of factory method will create new instance.
• Subdivisions and languages databases are large, so they have now optimisation to load entries from separate files instead of one single file..