Latest version causes an exception in ts-jest

[mmomtchev]

    TypeError: Cannot assign to read only property 'Symbol(Symbol.toStringTag)' of object '#<QuickLRU>'

      at node_modules/quick-lru/index.js:278:22
      at Object.<anonymous> (node_modules/quick-lru/index.js:1:1)

Symbol.toStringTag should be a getter, not a function

geotiffjs/geotiff.js#292