I wanted to let anyone trying to make a new DFU project know that there seems to be an error in the quick start guide (QSG) included with the DFU library.
Step 3.2 Specifies for a post build signing command to be added to the App0 project. I found that if I included this command then the the chip programming would fail saying it tried to write a part of memory it didn't have access to. After removing that step I was able to successfully setup the example.
Perhaps a CY_SECTION(".cy_app_signature") is needed but I did not go back and try to add this.