Added tests for instantiating and hash creation of a fake tx with and without from set
Added tests for instantiating and hash creation of a fake tx with and without from set

ethereumjs/ethereumjs-vm,ethereum/ethereumjs-tx,ethereumjs/ethereumjs-vm,ethereumjs/ethereumjs-vm,ethereumjs/ethereumjs-vm,ethereum/ethereumjs-vm,ethereumjs/ethereumjs-tx,ethereumjs/ethereumjs-tx,ethereumjs/ethereumjs-vm