travis CHANGE move to Ubuntu Xenial (16.04)
diff --git a/.travis.yml b/.travis.yml
index c6ccb76..a4dda08 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,6 @@
 language: c
 sudo: required
-dist: trusty
+dist: xenial
 branches:
   only:
     - libyang2
@@ -34,7 +34,7 @@
           branch_pattern: libyang2
       before_install:
         # check if something changed from the last coverity build
-        - if [ `git rev-parse HEAD` = `cat $HOME/cache/coveritybuild` ]; then echo "Codebase did not change from previous build."; travis_terminate 0; fi
+        - if [ "`git rev-parse HEAD`" = "`cat $HOME/cache/coveritybuild`" ]; then echo "Codebase did not change from previous build."; travis_terminate 0; fi
         - if [ ! -d $HOME/cache ]; then mkdir -p $HOME/cache; fi
         - git rev-parse HEAD > $HOME/cache/coveritybuild
         # get everything for coverity