build CHANGE use libyang's devel branch in Travis CI
diff --git a/.travis.yml b/.travis.yml
index dd8c54d..7755bda 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -30,6 +30,7 @@
 
   - git clone https://github.com/CESNET/libyang.git
   - mkdir libyang/build && cd libyang/build
+  - git checkout devel
   - cmake -DCMAKE_INSTALL_PREFIX:PATH=/usr .. && make -j2 && sudo make install
   - cd ../..