Don't download line items if we're just looking for totals
fix order for GET requests, it is not OrderBy but simply order
add UpdatedDateUTC to Payments, retrieve as updated_at on the object
Merge branch 'add_updated_at_to_payments' into develop
Merge branch 'mainrepo_master' into dont-download-line-items-unless-we-have-to

Conflicts:
	Gemfile.lock
	lib/xero_gateway/line_item_calculations.rb
Merge pull request #48 from nikz/dont-download-line-items-unless-we-have-to

Don't download line items if we're just looking for totals
Added functionality for get_payments
Removed unused invalid payment id constant
Removed pry from test and gateway param from payment from_xml
Merge pull request #59 from felixibel/add_get_payments

Add get payments
Fixed wrong params for payments from_xml and added tests for gateway get methods
Merge pull request #61 from felixibel/fix_get_payments

Fix: get_payments params