message: CHANGELOG: add 3.0.0 changelog
diff: +# 3.0.0
  +From this release users can expect out-of-the-box Segregated Witness support.
  +The majority of breaking changes have been in how `script` encoding/decoding occurs, with the introduction of witness stacks.
  +
  +__added__
  +- Added `script.types` enums (#679)
  +- Added `script.*.*.{check,encode,decode[,encodeStack,decodeStack]}` functions (#681, #682)
  +- Added minimal `TransactionBuilder.prototype.build` absurd fee-safety (#696)
  +- Added `script.(decompile/compile)PushOnly` and `script.toStack` functions (#700)
  +- Added `Transaction.prototype.toBuffer` Segregated Witness serialization support (#684, #701)
  +- Added `Transaction.prototype.hasWitnesses` (#718)
  +- Added `script.witnessCommitment.*` template
  +
  +__fixed__
  +- Fixed `script` must compile minimally (#638)
  +- Fixed `Transaction` and `Block` versions should be Int32, signed integers (#662)
  +
  +__removed__
  +- Removed `ecdsa.calcPubKeyRecoveryParam`, `ecdsa.recoverPubKey` (#456)
  +- Removed `buffer-equals`/`buffer-compare` dependencies (#650)
  +- Removed `HDNode.prototype.toString` (#665)
  +- Removed `dogecoin` network (#675)
  +
  +__renamed__
  +- Removed `script.*` functions in favour of `bitcoin.script.*.(input/output).(encode/decode/check)` style (#682)
  +
  # 2.3.0
  __added__
  - Added `HDNode.prototype.isNeutered` (#536)
  