Merge pull request #2 from qutonic/master

proposing a refactor, better error handling, and initialisation changes
update readme
fix failing tests
add refunds and tests
one more test
post tests
add method to refund a charge
add collection response wrapper to handle paging.
1.0
1.0 (update date)
add rubygems details
add travis.yml
require ruby 1.9
fix travis.ci image
wording
tidy up readme
add searching for charges
1.1
update readme with charge searching
1.2, gitignore gemfile.lock