Add a basic travis file for unit tests

Only code formatting implemented at the moment.

  Travis is currently Ubuntu 14.04, which is missing multiple library versions needed. Bootstrapping in Python 3.5, Meson and Ninja is possible, but can take a while, but also bootstrapping in libsystemd is one step too many for now as it takes a significant amount of time.

.travis.yml

@@ -0,0 +1,11 @@
+language: c
+compiler: gcc
+sudo: false
+
+addons:
+  apt:
+    packages:
+      - clang-format-3.4
+
+script:
+  - ./scripts/format-check.sh