ci: mynewt: Enable Mynewt specific tests

This allows to run Mynewt bootserial tests in CI.

Signed-off-by: Szymon Janc <szymon.janc@codecoup.pl>
diff --git a/ci/mynewt_run.sh b/ci/mynewt_run.sh
index c84dccf..6639662 100755
--- a/ci/mynewt_run.sh
+++ b/ci/mynewt_run.sh
@@ -25,4 +25,9 @@
     [[ $? -ne 0 ]] && exit 1
 done
 
+mkdir targets
+cp -r repos/apache-mynewt-core/targets/unittest targets
+newt test boot/boot_serial
+[[ $? -ne 0 ]] && exit 1
+
 exit 0