v0.6.0-rc3

Changelog

• Refactor traceTransactions and estimateFee, and rename STRK to FRI by @ArielElp in #174
  • use the name fri for $10^{-18}$ strk
  • added TRANSACTION_EXECUTION_ERROR
  • added the SKIP_VALIDATE flag to starknet_estimateFee
  • clarified semantics of simulate and estimate: simulateTransactions should provide traces whenever possible and reply with TRANSACTION_EXECUTION_ERROR in cases of validation failure or internal error. estimateFee however is expected to fail with TRANSACTION_EXECUTION_ERROR when a transaction reverts, in order to avoid a scenario where transactions that are known to revert are sent to the network by mistake.

• add units to FEE_ESTIMATE by @ArielElp in #175

Full Changelog: v0.6.0-rc2...v0.6.0-rc3