Currently, install requres a Linux swap partition to exist before the install can proceed. Ironically, a subsequent screen permits you to not use a swap partition and continue. On today's large memory systems, it should be permitted to install and run Linux without a swap partition at all. Current workaround: make a 1 MB (or single-cylinder) swap partition
Performing the installation in "expert" mode will allow you to get around this requirement. This is not a bug in the system, but rather a safety feature.