Issue installing on M1 Mac

[andeElliott]

When trying to install on an M1 mac the following error occurs:

clang: warning: argument unused during compilation: '-msse2' [-Wunused-command-line-argument]
error: unknown FP unit 'sse'
make: *** [RcppExports.o] Error 1
ERROR: compilation failed for package ‘netdist’

• removing ‘/Library/Frameworks/R.framework/Versions/4.2-arm64/Resources/library/netdist’
  Warning message:
  In i.p(...) :
  installation of package ‘/var/folders/1y/rvp35fsx51q68twjxjtrqwjm0000gp/T//RtmpptAHQz/filedec5c4b361d/netdist_0.4.9000.tar.gz’ had non-zero exit status

We wanted this argument to make sure that that Kahan summation worked, but it is causing issues on M1, perhaps we need a switch to turn this on, in x86, and turn it off on M1 (and possibly other arm processors?)

@martintoreilly thoughts?

[ots22]

See #138