Wrong arch value in install.sh on Raspbery PI

[MyAir]

The logic to figure out the os and arch for binary fetching in install.sh is flawed.
On my RaspberryPi uname -a looks like this:
Linux greenpi 4.1.20-v7+ #862 SMP Sat Mar 19 20:37:37 GMT 2016 armv7l GNU/Linux
the case for the x86 architecture *i*86* matches my kernel version in error and the script thinks my arch is x86 rather than arm-pi due to armv71.
so this case block must be improved:

  case "$uname" in
    *x86_64*) arch=x64 ;;
    *i*86*) arch=x86 ;;
    *armv6l*) arch=arm-pi ;;
    *armv7l*) arch=arm-pi ;;
  esac

(sorry it's my first entry on github. That's the best i can explain it)