dist/tools/compile_test: use Python3
dist/tools/compile_test: use Python3

authmillenon/RIOT,jasonatran/RIOT,kaspar030/RIOT,kYc0o/RIOT,ant9000/RIOT,authmillenon/RIOT,OlegHahm/RIOT,ant9000/RIOT,OTAkeys/RIOT,OlegHahm/RIOT,kaspar030/RIOT,miri64/RIOT,kaspar030/RIOT,RIOT-OS/RIOT,miri64/RIOT,authmillenon/RIOT,jasonatran/RIOT,miri64/RIOT,RIOT-OS/RIOT,miri64/RIOT,authmillenon/RIOT,kYc0o/RIOT,jasonatran/RIOT,authmillenon/RIOT,OTAkeys/RIOT,kaspar030/RIOT,ant9000/RIOT,ant9000/RIOT,authmillenon/RIOT,OlegHahm/RIOT,miri64/RIOT,OTAkeys/RIOT,OlegHahm/RIOT,OlegHahm/RIOT,kYc0o/RIOT,kaspar030/RIOT,kYc0o/RIOT,RIOT-OS/RIOT,jasonatran/RIOT,RIOT-OS/RIOT,ant9000/RIOT,jasonatran/RIOT,OTAkeys/RIOT,RIOT-OS/RIOT,kYc0o/RIOT,OTAkeys/RIOT