update travis

Author: wasabeef

.travis.yml

@@ -17,6 +17,11 @@ env:
 before_install:
     # Making sure gradlew has executable permissions
     - chmod +x gradlew
+    - wget http://dl.google.com/android/ndk/android-ndk-r10c-linux-x86_64.bin		
+    - chmod +x android-ndk-r10c-linux-x86_64.bin		
+    - ./android-ndk-r10c-linux-x86_64.bin | egrep -v ^Extracting		
+    - export ANDROID_NDK_HOME=`pwd`/android-ndk-r10c		
+    - export PATH=${PATH}:${ANDROID_NDK_HOME}
 
 android:
   components: