Fix bug if error response does not have data
Fix: payment_sum should be payment_total
Merge pull request #751 from sharetribe/minor-paypal-fixes

Minor paypal fixes
Save minimum commission to transaction
Txn fee and min price UI
Save to database
parse_str_to_money to parse money strings
Commission validation
Front-end validation
Finalize UI
Finalize translations
Disable Rails field_with_error wrapper
h3 -> label
Remove roundings, show minimum commission to user
Fixed bugs related to minimum price, translations
Remove roundings also from specs
Fix JS lint
Minimum price is 0 if it's null
Remove roundings from cucumber tests
Doc update: Transaction service create does not take min comms. param