build: Update Android target revision
diff --git a/.travis.yml b/.travis.yml
index c976d41..5a47aeb 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,7 +10,7 @@
     # Android build.
     - os: linux
       compiler: gcc
-      env: VULKAN_BUILD_TARGET=ANDROID ANDROID_TARGET=android-21 ANDROID_ABI=armeabi-v7a
+      env: VULKAN_BUILD_TARGET=ANDROID ANDROID_TARGET=android-23 ANDROID_ABI=armeabi-v7a
     # Linux GCC debug build.
     - os: linux
       compiler: gcc
@@ -20,6 +20,13 @@
       compiler: clang
       env: VULKAN_BUILD_TARGET=LINUX
 
+android:
+  components:
+    - tools
+    - platform-tools
+    - build-tools-23.0.2
+    - android-23
+
 before_install: 
   # Install the appropriate Linux packages.
   - if [[ "$VULKAN_BUILD_TARGET" == "LINUX" ]]; then