Add a minimal .travis.yml for Travis CI. Some ugly hacks needed to get RocksDB...

Add a minimal .travis.yml for Travis CI. Some ugly hacks needed to get RocksDB building in Travis' OpenVZ Ubuntu 12.04 environment.

.travis.yml

+language: cpp
+compiler: gcc
+before_install:
+# As of this writing (10 May 2014) the Travis build environment is Ubuntu 12.04,
+# which needs the following ugly dependency incantations to build RocksDB:
+ - sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test
+ - sudo apt-get update -qq
+ - sudo apt-get install -y -qq gcc-4.8 g++-4.8 zlib1g-dev libbz2-dev libsnappy-dev libjemalloc-dev
+ - sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-4.8 50
+ - sudo update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-4.8 50
+ - wget https://gflags.googlecode.com/files/libgflags0_2.0-1_amd64.deb
+ - sudo dpkg -i libgflags0_2.0-1_amd64.deb
+ - wget https://gflags.googlecode.com/files/libgflags-dev_2.0-1_amd64.deb
+ - sudo dpkg -i libgflags-dev_2.0-1_amd64.deb
+# Lousy hack to disable use and testing of fallocate, which doesn't behave quite
+# as EnvPosixTest::AllocateTest expects within the Travis OpenVZ environment.
+ - sed -i "s/fallocate(/HACK_NO_fallocate(/" build_tools/build_detect_platform
+script: make check -j8
+