Mac install should check for Rosetta mode

[garfieldnate]

Use sysctl -n sysctl.proc_translated, which returns 1 when running under Rosetta and 0 otherwise. If running under Rosetta, we should install the x86-64 binaries, not the ARM64 ones.

if [ $(sysctl -n sysctl.proc_translated) ]
then
    echo "Rosetta"
else
    echo "Not Rosetta"
fi