travis: Add a travis.yml for doing CI after commits

Instruct travis-ci to build systemd and create a tarball. In case
of an error travis-ci will complain on IRC. The systemd testsuite
currently requires the host to have a recent version of systemd
installed and running. This is not the case for the Ubuntu VM of
travis-ci. This means make check and make distcheck will result in
a build failure and to avoid this these commands are not executed.

This requires a one time configuration on travis-ci for the repo
on github by the owner of the repo.

.travis.yml

@@ -0,0 +1,13 @@
+language: c
+compiler:
+  - gcc
+before_install:
+ - sudo apt-get update -qq
+ - sudo apt-get install autotools-dev automake autoconf libtool libdbus-1-dev libcap-dev libblkid-dev libpam-dev libcryptsetup-dev libaudit-dev libacl1-dev libattr1-dev libselinux-dev liblzma-dev libgcrypt-dev libqrencode-dev libmicrohttpd-dev gtk-doc-tools gperf
+script: ./autogen.sh && ./configure --enable-gtk-doc --enable-gtk-doc-pdf && make V=1 && make dist V=1
+notifications:
+  irc:
+    channels:
+      - "irc.freenode.org#systemd"
+    on_success: change
+    on_failure: always