Install alsa. Drop Clang. Drop PNG

.travis.yml

@@ -14,7 +14,9 @@ matrix:
           packages:
             - g++-5
             - libjpeg8-dev
-            - libpng-dev
+            - libasound2-dev
+            - alsa-utils
+            - alsa-oss
           sources: &sources
             - ubuntu-toolchain-r-test
             - llvm-toolchain-precise
@@ -26,31 +28,9 @@ matrix:
           packages:
             - g++-4.9
             - libjpeg8-dev
-            - libpng-dev
+            - libasound2-dev
-          sources: *sources
+            - alsa-utils
-    - env: CXX=clang++-3.8 CC=clang-3.8
+            - alsa-oss
-      addons:
-        apt:
-          packages:
-            - clang-3.8
-            - libjpeg8-dev
-            - libpng-dev
-          sources: *sources
-    - env: CXX=clang++-3.7 CC=clang-3.7
-      addons:
-        apt:
-          packages:
-            - clang-3.7
-            - libjpeg8-dev
-            - libpng-dev
-          sources: *sources
-    - env: CXX=clang++-3.6 CC=clang-3.6
-      addons:
-        apt:
-          packages:
-            - clang-3.6
-            - libjpeg8-dev
-            - libpng-dev
           sources: *sources
 
 before_install:
@@ -67,5 +47,5 @@ before_script :
   - cd bld
 
 script:
-  - cmake -G"Unix Makefiles" .. -DENABLE_JPEG=ON -DENABLE_PNG=ON
+  - cmake -G"Unix Makefiles" .. -DENABLE_JPEG=ON
   - make