QTestLib require GUI support for some tests.

--HG--
branch : develop

.travis.yml

@@ -21,6 +21,9 @@ before_install:
   - sudo apt-get install -y libqt5core5 libqt5gui5 libqt5printsupport5 libqt5svg5 libqt5widgets5 libqt5xml5 libqt5xmlpatterns5 xpdf cppcheck
 
 before_script:
+  # QTestLib require GUI support for some tests
+  - "export DISPLAY=:99.0"
+  - "sh -e /etc/init.d/xvfb start"
   - mkdir build
   - cd build
   - which qmake
@@ -31,7 +34,7 @@ before_script:
 script:
   - cppcheck --error-exitcode=1 --quiet --inline-suppr --template '{file}:{line}:{message}:{id}' --std=posix --enable=performance,portability ../src
   - make -j$(nproc)
-  - make check
+  - DISPLAY=:99.0 make check
 
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