Revert "Try using etc.linux.memoryerror when running unit tests on Linux"

This reverts commit e4d785a561f078b9e5de23bd13e8b11614f146b5.
Revert "Check if using LuaJIT is a workaround for #35 on debian-amd64 travis servers"

This reverts commit ebc32032195389b76717b1aacd463b438ed44c38.