Hi.  I am doing the tralhead https://trailhead.salesforce.com/modules/lex_javascript_button_migration/units/javascript_buttons_to_lightning_actions

I have attempted to do this tralhead for about 3 weeks now -- sent in some feedback, but no change seems apparent in the tralhead.

1.  I created a brand new "My Trailhead Playground 2"
2.  Open the Developer console.
3.  Create a Lightning Component called CreateUser.cmp
4.  Copy the text in for this code.
5.  Press Save
6.  Get Error.  Failed to save CreateUser.cmp: Invalid <aura:attribute> type: Test_User__c: Source

In order for this to save, I had to create an object Test_User (Test_User__c) with the following fields:
First or First__c
Last or Last__c
Nickname or Nickname__c
Email or Email__c
Password or Password__c

I also had to change several lines of code to reflect the Field name xxx__c rather than what was listed in the tralhead.
value="{!v.user.First}"  to value="{!v.user.First__c}"  etc.

I haven't finished with the tralhead examples...but I hope this will work.

Would someone please update the tralhead or fix it?

Thanks,
Stuart