I, [JUL 11 2014 7:21:44 PM +0000#15619] INFO -- : Fetching exchange rates
Digest::Digest is deprecated; use Digest
/home/ubuntu/.rbenv/versions/2.1.2/lib/ruby/2.1.0/net/http/header.rb:17:in `block in initialize_http_header': undefined method `strip' for nil:NilClass (NoMethodError)
from /home/ubuntu/.rbenv/versions/2.1.2/lib/ruby/2.1.0/net/http/header.rb:15:in `each'
from /home/ubuntu/.rbenv/versions/2.1.2/lib/ruby/2.1.0/net/http/header.rb:15:in `initialize_http_header'
from /home/ubuntu/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/httparty-0.13.1/lib/httparty/request.rb:152:in `setup_raw_request'
from /home/ubuntu/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/httparty-0.13.1/lib/httparty/request.rb:90:in `perform'
from /home/ubuntu/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/httparty-0.13.1/lib/httparty.rb:521:in `perform_request'
from /home/ubuntu/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/httparty-0.13.1/lib/httparty.rb:457:in `get'
from /home/ubuntu/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/coinbase-1.3.0/lib/coinbase/client.rb:201:in `http_verb'
from /home/ubuntu/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/coinbase-1.3.0/lib/coinbase/client.rb:174:in `get'
from /home/ubuntu/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/coinbase-1.3.0/lib/coinbase/client.rb:133:in `buy_price'
from /home/bitcoin/rbtc_arbitrage/lib/rbtc_arbitrage/clients/coinbase_client.rb:40:in `price'
from /home/bitcoin/rbtc_arbitrage/lib/rbtc_arbitrage/trader.rb:78:in `fetch_prices'
from /home/bitcoin/rbtc_arbitrage/lib/rbtc_arbitrage/trader.rb:38:in `trade'
from /home/bitcoin/rbtc_arbitrage/lib/rbtc_arbitrage/cli.rb:14:in `trade'
from /home/ubuntu/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/thor-0.18.1/lib/thor/command.rb:27:in `run'
from /home/ubuntu/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/thor-0.18.1/lib/thor/invocation.rb:120:in `invoke_command'
from /home/ubuntu/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/thor-0.18.1/lib/thor.rb:363:in `dispatch'
from /home/ubuntu/.rbenv/versions/2.1.2/lib/ruby/gems/2.1.0/gems/thor-0.18.1/lib/thor/base.rb:439:in `start'
from ./bin/rbtc:5:in `<main>'
rbtc --seller bitstamp --buyer coinbase