ci: add threshold example

Signed-off-by: Markus Klotzbuecher <mk@mkio.de>

.travis.yml

@@ -56,11 +56,13 @@ script:
   - ./run_tests.sh
   # test generating an out-of-tree block
   - ubx-genblock -d /tmp/testblock/ -c examples/blockmodels/block_model_example.lua
-  - cd /tmp/testblock/
+  - pushd /tmp/testblock/
   - ./bootstrap
   - ./configure
   - make
   - sudo make install
   - ubx-launch -t 1 -webif -c myblock.usc
+  - popd
+  - ubx-launch -t 3 -s -check -c unconn_inports,unconn_outports examples/usc/threshold.usc
   - cd /usr/share/ubx/examples/usc/pid/
   - ubx-launch -t 3 -s -check unconn_inports,unconn_outports -c pid_test.usc,ptrig_nrt.usc