Update Travis badge
Add setters to resources
Make appropriate resource attributes readonly
Add API calls for Orders
Implement item API calls
Extract resource operations
Add API operations to LineItem class
Rename Operations to Actions
Extract actions
Add list and retreive to Campaign
Implement get request
Implement post request
Implement patch request
Implement delete request
Add query params to get requests
Extract API and Error classes
Migrate API request specs
Delete specs testing API directly against PF module
Bump Travis rubies
Remove Rubinius from Travis config for Bundler issues