fix test failing on ruby 2.0
fix test failing on ruby 2.0

We are only adding @addr in before, so expectation wasn't matching for
newly generated key, I still have no idea why it wasn't failing on 1.9

georgemillo/bitcoin-ruby,Zlerp/bitcoin-ruby,tarix/bitcoin-ruby,assafshomer/bitcoin-ruby,bitpesa/bitcoin-ruby,xiumiao/bitcoin-ruby,robertg/bitcoin-ruby,mhanne/bitcoin-ruby