initial travis-ci support

.travis.yml

+language: cpp
+
+git:
+  depth: 100
+
+os:
+  - linux
+  - osx
+
+cache:
+  apt: true
+
+env:
+  - CONFIG=release
+  - CONFIG=debug
+
+before_install:
+  - cd ${TRAVIS_BUILD_DIR} && git fetch --unshallow
+
+install:
+  - if [ "${TRAVIS_OS_NAME}" = "linux" ]; then
+         sudo apt-add-repository -y ppa:ubuntu-toolchain-r/test
+      && sudo apt-add-repository -y ppa:beineri/opt-qt541
+      && sudo apt-get -qq update
+      && sudo apt-get -qq install g++-4.8 libc6-i386 qt54tools qt54base qt54declarative qt54serialport qt54svg qt54webkit qt54quickcontrols qt54xmlpatterns qt54x11extras qt54websockets qt54sensors qt54script qt54quick1 qt54multimedia qt54location qt54imageformats qt54graphicaleffects qt54connectivity espeak libespeak-dev libopenscenegraph-dev libsdl1.2-dev libudev-dev
+      && export CXX="g++-4.8"
+      && export CC="gcc-4.8"
+      ;
+    else
+         brew update
+      && brew install qt5
+      && chmod -R 755 /usr/local/opt/qt5/*
+      ;
+    fi
+  - export DISPLAY=:99.0
+  - sh -e /etc/init.d/xvfb start
+
+before_script: /opt/qt54/bin/qmake CONFIG+=${CONFIG} -r qgroundcontrol.pro
+script:
+  - make -j4
+#  - if [ "${CONFIG}" = "debug" ]; then ./debug/qgroundcontrol --unittest; fi
+
+#deploy:
+#  provider: releases
+#  api-key:
+#    secure: ""
+#  file: "release/qgroundcontrol"
+#  skip_cleanup: true
+#  on:
+#    tags: true
+#    all_branches: true