add metainfo test

Signed-off-by: Stephan Lachnit <stephanlachnit@protonmail.com>

.travis.yml

@@ -5,6 +5,7 @@ sudo: false
 addons:
   apt:
     packages:
+      - appstream
       - clang
       - clang-format
       - libinih-dev
@@ -18,6 +19,7 @@ addons:
 script:
   - ./scripts/format-check.sh
   - ./bootstrap.sh -Dwith-examples=true
+  - meson test -C build
   - gamemoded -v
   - dbus-run-session -- gamemode-simulate-game
   - ./scripts/static-analyser-check.sh