Stop testing against x86 variants
Stop testing against x86 variants

Appveyor build is currently quite slow, and these entries have never
discovered a single issue, so let's remove them.

deivid-rodriguez/byebug,deivid-rodriguez/byebug,yui-knk/byebug,deivid-rodriguez/byebug,yui-knk/byebug,yui-knk/byebug