sdk relocation silently fails if python isn't installed

[fboudra]

I was debugging zephyr sdk installation in our build farm, trying to figure out why it didn't work on some slaves.
It appears we call relocate_sdk.py during the installation process and obviously depends on python available.
Since our build slaves have only the bare minimal OS, python wasn't available and relocate_sdk.py silently failing the relocation.

To reproduce, without python installed:
./zephyr-sdk-0.8.2-i686-setup.run --quiet --nox11 -- <<< "${HOME}/zephyr-sdk-0.8.2"

You'll end with a non-working Zephyr SDK installation.

[jurobystricky]

Thanks for bringing this up. I will need to add some tests for python presence.
Incidentally, this meta-zephyr GIT repo has been superseded by meta-zephyr-sdk in:
https://gerrit.zephyrproject.org/r/gitweb?p=meta-zephyr-sdk.git;a=summary