Rapyd: Add fields and update stored credential method

[yunnydang]

This change is allow users to manage NTID themselves by adding an option for them to pass in the fields network_reference_id and initiation_type directly.

Local:
5588 tests, 77761 assertions, 0 failures, 19 errors, 0 pendings, 0 omissions, 0 notifications 99.66% passed

Unit:
27 tests, 137 assertions, 0 failures, 0 errors, 0 pendings, 0 omissions, 0 notifications 100% passed

Remote:
34 tests, 95 assertions, 0 failures, 0 errors, 0 pendings, 0 omissions, 0 notifications 100% passed

[rachelkirk]

This looks good, just had a few small suggestions.

[rachelkirk]

Two things here:

1. I would create this NTID override as options[:network_transaction_id] to keep it consistent across other gateways that have this override (even though Rapyd calls it something else)
2. I would use the ternary operator here. Something like
   network_reference_id = options[:network_transaction_id] ? options[:network_transaction_id] : options[:stored_credential][:network_transaction_id]. That might be a little cleaner. You could also use this in the add_initiation_type method below.

[yunnydang]

Thanks for the suggestions, it totally looks cleaner this way!

[yunnydang]

I was running into rubocop errors when writing it network_reference_id = options[:network_transaction_id] ? options[:network_transaction_id] : options[:stored_credential][:network_transaction_id] as it's stating it was an unneeded conditional. The new way I wrote is the same as it'll prioritize the GSF if it's present and then default to the stored_credential hash. Also updated the tests and variable names to reflect network_transaction_id like you suggested and also added another assertion to the remote test when sending both stored credentials and options, thanks a bunch!

[rachelkirk]

Looks good! Nice refactoring! (Approving, but you need to fix up the conflict in your unit test file)