Add Travis CI configuration
Merge pull request #21 from allolex/add_travis

Add Travis CI configuration
Make tests pass under MRI 1.9.3, Rubinius and jruby
Fix Travis CI errors for Rubinius

Rubinius no longer includes the standard library as part of core, so standard library gems need to be loaded explicitly.
Fix Gemfile path
Tell Travis to install the coverage gem for rubinius
Install json gem for rubinius
Merge pull request #22 from allolex/multiple_rubies

Make tests pass under MRI 1.9.3, Rubinius and jruby
Upgrade Ruby to 2.1
Add Connection#cancel

- Changed Api::Response to handle optional and fewer fields
- Tested both failure response and success for #cancel
- Add cancellation path to Circle CI environment
- Add cancel path environment variable to Travis
- Remove redundant connection_v03 spec
Move Connection#post and #cancel fully into shared examples
- Use do…end or single line let statements with curly braces
Make method names internally consistent

Rename valid_failure_response to post_failed_response_body to be consistent with cancel_failed_response_body.
Merge pull request #23 from Curatur/cancel_request

Allow user to cancel API processing
Add TravisCI build passing image
Link build status image to Suretax's Travis CI page