run_ci.sh: run pytest-3 if found
run_ci.sh: run pytest-3 if found

On (at least) Fedora "pytest" is python2 and python2 only.

Also update remote name in sample invocation from "upstream" to "origin"
because that's how west sets things up by default (and this script
requires west)

Signed-off-by: Marc Herbert <77e7c7d746b52c6eb01119b65a031ae1f650246d@intel.com>

finikorg/zephyr,galak/zephyr,Vudentz/zephyr,galak/zephyr,nashif/zephyr,GiulianoFranchetto/zephyr,nashif/zephyr,nashif/zephyr,finikorg/zephyr,nashif/zephyr,Vudentz/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,ldts/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,nashif/zephyr,GiulianoFranchetto/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,ldts/zephyr,Vudentz/zephyr,finikorg/zephyr,Vudentz/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,ldts/zephyr,galak/zephyr,ldts/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,Vudentz/zephyr