build: Enable TravisCI build testing

It will provide an Ubuntu 14.04 LTS virtual machine (Trusty Beta):

  https://docs.travis-ci.com/user/ci-environment/

Signed-off-by: Namhyung Kim <namhyung@gmail.com>

.travis.yml

@@ -0,0 +1,12 @@
+language: c
+
+# Ubuntu 14.04 LTS
+dist: trusty
+
+sudo: required
+
+install:
+- sudo apt-get -qq update
+- sudo apt-get -y  install libelf-dev libstdc++-4.8-dev pandoc
+
+script: ./configure && make