Added pry gem for debug
Remove useless boolean return for expire_rates
test: expire_rates implementation testing
Bump to 0.1.7
travis: added config
update money gem to 6.2.1
README: update
travis: cache bundle remove 1.9.3,jruby
Revert "travis: cache bundle remove 1.9.3,jruby"

This reverts commit eef6c3d12fde49ab24d4d9940da30a843e1be35b.
tests: @bank to subject
tests: unify raise testing
use exchange_with and get_rate from VariableExchange
travis: remove jruby-head
update contributors and authors
Bump to 0.2.0
README: added badges [ci skip]
travis: cache bundler
setup reverse rates (ie. XYZ -> USD)
adjust tests to intentionally remove AED from data file and test conversions to AED
Doc save_rates and code cleanup