[smuxi: 6/12] travisCI: from old trusty(14.04) to xenial(16.04)

[Mirco M. M. Bauer <mmmbauer src gnome org>]

commit 0513b9c54279cefa454596c020e1c7e001421780
Author: Andres G. Aragoneses <knocte gmail com>
Date:   Wed Dec 5 13:19:08 2018 +0800

    travisCI: from old trusty(14.04) to xenial(16.04)
    
    Trusty is a bit ancient these days (https://twitter.com/directhex/status/1068531931648643074).
    At the time of writing this part of the travis YML, there might have not been support for xenial
    but now there is: https://docs.travis-ci.com/user/reference/overview/

 .travis.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.travis.yml b/.travis.yml
index 2ae13211..13c5cb0c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,5 @@
 language: csharp
-dist: trusty
+dist: xenial
 
 before_install:
   - git submodule update --init --recursive