Transaction.encode() should be renamed encodeTxWith()

[SergioDemianLerner]

The method encodes the transaction, not only the signature given in the arguments v,r and s. The name encode(v,r,s) suggests that what is encoded are the arguments.

[Vovchyk]

hmm.. if Transaction.encode() was a static method, then yes we could consider v, r and s as the ones being encoded. But Transaction.encode() is an instance method, eg. same as String.substring(index). More over, it's a private one, so is not exposed outside. Personally, I don't see confusion here, but feel free to make a pr with the suggested change - I believe the impact is close to zero.