optional use coinbase blockexplorer in examples/bbe_verify_tx.rb
optional use coinbase blockexplorer in examples/bbe_verify_tx.rb

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