backend-tests: make runnable from anywhere
backend-tests: make runnable from anywhere

either by:
./integration/backend-tests/run or
cd ./integration/backend-tests && ./run

changelog: none

Signed-off-by: mchalczynski <3a897b56ed6fc284ae11e3e7ec3ea48d098a7178@rndity.com>

pasinskim/integration,pasinskim/integration,pasinskim/integration