ci: add travis support

For now, do not run tests as they require sudo privileges. In the near
future, a plan will be devised to automate testing.

Signed-off-by: Levente Kurusa <lkurusa@acm.org>

.travis.yml

@@ -0,0 +1,11 @@
+language: rust
+rust:
+  - stable
+  - beta
+  - nightly
+matrix:
+  allow_failures:
+    - rust: nightly
+  fast_finish: true
+script:
+  - cargo build --verbose --all