0.15.0

Additions

• Added in-memory cache for ledger.
• Added option disableIndex for faster startup in scenarios where you don't
  have to query the index.
• Added option ledgerCacheSize to control how much of the ledger to cache in
  memory, for faster retrieval.
• Added command open:noindex to cli-tool.

Changes

• Refactor of cli tool.
• Added the .scan() method to extract full transaction history for a certain
  key.
• Fixed various bugs.

Full Changelog: 0.14.0...0.15.0