build the example server for coverage

.travis.yml

@@ -89,7 +89,7 @@ script:
 - make 
 - cd .. && rm build -rf && mkdir -p build && cd build
 - echo "Debug build and unit tests (64 bit)"
-- cmake -DCMAKE_BUILD_TYPE=Debug -DBUILD_DEMO_NODESET=ON -DBUILD_UNIT_TESTS=ON -DENABLE_COVERAGE=ON ..
+- cmake -DCMAKE_BUILD_TYPE=Debug -DBUILD_DEMO_NODESET=ON -DBUILD_UNIT_TESTS=ON -DBUILD_EXAMPLESERVER=ON -DENABLE_COVERAGE=ON ..
 - make && make test
 - echo "Run valgrind to see if the server leaks memory (just starting up and closing..)"
 - valgrind --error-exitcode=3 ./server & export pid=$!; sleep 2; kill -INT $pid; wait $pid