Add fast finish to travis

Now, a build will finish as soon as a job has failed, or when the only
jobs left allow failures.

See https://docs.travis-ci.com/user/customizing-the-build/#Fast-Finishing

Signed-off-by: Christoph <auer.chrisi@gmx.net>

.travis.yml

@@ -3,6 +3,7 @@ sudo: required
 language: cpp
 
 env:
+  matrix:
    - BUILD_VERSION=""
    - BUILD_VERSION="disable_autoupdate"
    - BUILD_VERSION="disable_register_custom_scheme"
@@ -11,6 +12,9 @@ env:
    - BUILD_VERSION="disable_desktop_file_generation"
    - BUILD_VERSION="disable_unity_integration"
 
+matrix:
+  fast_finish: true
+
 arch:
   repos:
    - home_ItachiSan_archlinux_Arch_Extra=http://download.opensuse.org/repositories/home:/ItachiSan:/archlinux/Arch_Extra/$arch