Add SDL2 support to travis config file

Author: AMDmi3

.travis.yml

@@ -4,12 +4,12 @@ compiler:
   - clang
 env:
   - CMAKE_FLAGS=""
-#  - CMAKE_FLAGS="-DWITH_SDL2=TRUE" # no SDL2 packages on travis
+  - CMAKE_FLAGS="-DWITH_SDL2=TRUE"
   - CMAKE_FLAGS="-DWITH_GTK2=FALSE -DWITH_GTK3=TRUE"
   - CMAKE_FLAGS="-DWITH_ICONV=FALSE"
   - CMAKE_FLAGS="-DSTANDALONE=TRUE"
 before_install:
+  - sudo add-apt-repository --yes ppa:zoogie/sdl2-snapshots
   - sudo apt-get update -qq
-#  - sudo apt-get install -qq cmake libsdl1.2-dev libsdl-image1.2-dev libsdl-mixer1.2-dev libsdl-ttf2.0-dev libsdl2-dev libsdl2-image-dev libsdl2-mixer-dev libsdl2-ttf-dev liblua5.1-0-dev libgtk2.0-dev libgtk-3-dev
-  - sudo apt-get install -qq cmake libsdl1.2-dev libsdl-image1.2-dev libsdl-mixer1.2-dev libsdl-ttf2.0-dev liblua5.1-0-dev libgtk2.0-dev libgtk-3-dev
+  - sudo apt-get install -qq cmake libsdl1.2-dev libsdl-image1.2-dev libsdl-mixer1.2-dev libsdl-ttf2.0-dev libsdl2-dev libsdl2-image-dev libsdl2-mixer-dev libsdl2-ttf-dev liblua5.1-0-dev libgtk2.0-dev libgtk-3-dev
 script: mkdir build && cd build && cmake ${CMAKE_FLAGS} .. && make