For Travis CI - wrap package installation steps with 'travis_retry'.

Occasionally package installation could fail due to timed out or other unknown one-off network issue, using 'travis_retry' wrapper to retry the installation should fix this.

.travis.yml

@@ -52,14 +52,14 @@ before_install:
     - bash -c "[ $ON_MASTER_COMMIT ]" && export RELEASE_TAG=$(git describe --tags --exact-match $TRAVIS_COMMIT 2>/dev/null) && bash -c "[ $RELEASE_TAG ]" && export PACKAGE_UPLOAD=1 || true
     - bash -c "[ $ANDROID ]" && wget -q http://dl.google.com/android/ndk/android-ndk-r9d-linux-x86_64.tar.bz2 && tar xjf *.bz2 && rm *.bz2 && ln -s android-ndk* android-ndk && export ANDROID_NDK=$(pwd)/android-ndk && bash -c "[ $PACKAGE_UPLOAD ]" && wget -q http://dl.google.com/android/android-sdk_r22.6.1-linux.tgz && tar xzf *.tgz && rm *.tgz && ln -s android-sdk* android-sdk && export ANDROID_SDK=$(pwd)/android-sdk || true
     - bash -c "[ $RPI ]" && git clone --depth 1 https://github.com/raspberrypi/tools.git rpi-tools && export RASPI_TOOL=$(pwd)/rpi-tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin && git clone --depth=1 https://github.com/urho3d/rpi-sysroot.git rpi-sysroot && export RASPI_ROOT=$(pwd)/rpi-sysroot || true
-    - bash -c "( [ $SITE_UPDATE_ON_MASTER_COMMIT ] || [ $PACKAGE_UPLOAD ] )" && sudo add-apt-repository ppa:george-edison55/precise-backports -y || true
-    - sudo apt-get update -q -y
+    - bash -c "( [ $SITE_UPDATE_ON_MASTER_COMMIT ] || [ $PACKAGE_UPLOAD ] )" && travis_retry sudo add-apt-repository ppa:george-edison55/precise-backports -y || true
+    - travis_retry sudo apt-get update -q -y
 install:
-    - sudo apt-get install -q -y --no-install-recommends libasound2-dev
-    - bash -c "[ x$URHO3D_64BIT == 'x' ]" && sudo apt-get remove -q -y gvfs-daemons && sudo apt-get install -q -y libxrandr-dev:i386 libglapi-mesa:i386 libgl1-mesa-glx:i386 libgl1-mesa-dev:i386 libxext-dev:i386 libxrender-dev:i386 g++-multilib && export CMAKE_PREFIX_PATH=/usr/lib/i386-linux-gnu || true
-    - bash -c "( [ $SITE_UPDATE_ON_MASTER_COMMIT ] || [ $PACKAGE_UPLOAD ] )" && sudo apt-get install -q -y --no-install-recommends doxygen graphviz || true
-    - bash -c "[ $WINDOWS ]" && sudo apt-get install -q -y gcc-mingw-w64 gcc-mingw-w64-i686 gcc-mingw-w64-x86-64 g++-mingw-w64 g++-mingw-w64-i686 g++-mingw-w64-x86-64 binutils-mingw-w64 binutils-mingw-w64-i686 binutils-mingw-w64-x86-64 && export MINGW_PREFIX=/usr/bin/${ARCH}-w64-mingw32 || true
-    - bash -c "( [ $LINUX ] || [ $RPI ] ) && [ $PACKAGE_UPLOAD ]" && sudo apt-get install -q -y rpm || true
+    - travis_retry sudo apt-get install -q -y --no-install-recommends libasound2-dev
+    - bash -c "[ x$URHO3D_64BIT == 'x' ]" && travis_retry sudo apt-get remove -q -y gvfs-daemons && travis_retry sudo apt-get install -q -y libxrandr-dev:i386 libglapi-mesa:i386 libgl1-mesa-glx:i386 libgl1-mesa-dev:i386 libxext-dev:i386 libxrender-dev:i386 g++-multilib && export CMAKE_PREFIX_PATH=/usr/lib/i386-linux-gnu || true
+    - bash -c "( [ $SITE_UPDATE_ON_MASTER_COMMIT ] || [ $PACKAGE_UPLOAD ] )" && travis_retry sudo apt-get install -q -y --no-install-recommends doxygen graphviz || true
+    - bash -c "[ $WINDOWS ]" && travis_retry sudo apt-get install -q -y gcc-mingw-w64 gcc-mingw-w64-i686 gcc-mingw-w64-x86-64 g++-mingw-w64 g++-mingw-w64-i686 g++-mingw-w64-x86-64 binutils-mingw-w64 binutils-mingw-w64-i686 binutils-mingw-w64-x86-64 && export MINGW_PREFIX=/usr/bin/${ARCH}-w64-mingw32 || true
+    - bash -c "( [ $LINUX ] || [ $RPI ] ) && [ $PACKAGE_UPLOAD ]" && travis_retry sudo apt-get install -q -y rpm || true
     - bash -c "[ $ANDROID ] && [ $PACKAGE_UPLOAD ]" && (while :; do echo 'y'; sleep 1; done) |android-sdk/tools/android update sdk --no-ui --filter platform-tool,build-tools-19.0.3,android-19,system-image,extra-android-support || true
     - bash -e /etc/init.d/xvfb start
 script: rake travis_ci