Fix actionpack dependency version
Update PayFast integration.
Check for required fields in the PayFast integration.
Update PayFast docs.
reapplying realex gateway addition changes
switch to service_url
Fix to realex timestamp generation
Amend changes to service_url to enable tests to pass
Whitespace fix and remove unnecessary line comment
Test Realex format_amount_as_float
Remove previously commented assertion from Realex notification test
Remove reference to Shopify
Use mocha stubs instead of override of OffsitePayments.mode
Implement billing/shipping code preparation for Realex AVS check