Try to get ninja-build running on Travis

.travis.yml

@@ -13,6 +13,8 @@ matrix:
             - check
             - libsubunit-dev
             - gcc-7
+            - ninja-build
+            - doxygen
       env:
         - LSAN_OPTIONS=verbosity=1:log_threads=1
 
@@ -26,17 +28,11 @@ matrix:
             - check
             - libsubunit-dev
             - clang-7
+            - ninja-build
+            - doxygen
       env:
         - LSAN_OPTIONS=verbosity=1:log_threads=1
 
-addons:
-  apt:
-    packages:
-      - check
-      - libsubunit-dev
-      - ninja-build
-      - doxygen
-
 before_install:
   # Install cmake
   - wget -O cmake.sh https://cmake.org/files/v3.12/cmake-3.12.0-Linux-x86_64.sh

travis.sh

@@ -20,7 +20,7 @@ cp contrib/examples/example_app/lwipcfg.h.travis contrib/examples/example_app/lw
 # Generate CMake
 mkdir build
 cd build
-/usr/local/bin/cmake ..
+/usr/local/bin/cmake .. -G Ninja
 
 # Build CMake
 ERR=$?