Port all users of 'set_conf_file' to use the built-in rules
instead. This follows the convention-over-configuration principle to
make the system as a whole simpler and more consistent.
Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>
Added tests for async UART API and test configuration for
nrf52840_pca10056 board.
For tests to work, RX and TX pins have to be connected together
and second UART is needed to output results to console.
Signed-off-by: Mieszko Mierunski <mieszko.mierunski@nordicsemi.no>
