Fix #113 (signed FakeTransaction)

[ajhodges]

Also serves as a contribution towards #114 .

This issue, discussed in #113, has a simple fix; a null check on the from setter. The bug is that if self._from is initialized to ethereumjs-util.toBuffer(null), it will contain a buffer object that represents '0'. Then if you call FakeTransaction.from, the getter will return that empty buffer object here (in getSenderAddress()):

if (this._from) {
  return this._from
}

This issue is currently preventing self-signed transactions from being submitted to ganache.

[coveralls]

Coverage increased (+0.01%) to 98.795% when pulling 1fb1b74 on ShipChain:master into 32989a3 on ethereumjs:master.

[holgerd77]

Thanks for working this out, looks good. Also great that you added to the tests, this is very much needed.

[holgerd77]

Released this as v1.3.7.