[smuxi: 113/179] Travis-CI: upgrade to new way of handling Mono (with 4 versions)

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

commit 9d14412bd607c024247d64b2446e8f41e91bdc9a
Author: Andres G. Aragoneses <knocte gmail com>
Date:   Sat Nov 12 19:48:40 2016 +0800

    Travis-CI: upgrade to new way of handling Mono (with 4 versions)

 .travis.yml |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)
---
diff --git a/.travis.yml b/.travis.yml
index cdc186d..179b67c 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,8 +1,14 @@
-language: c
+language: csharp
 
 before_install:
   - git submodule update --init --recursive
 
+mono:
+    - latest
+    - 4.2.3
+    - 4.0.0
+    - 3.12.0
+
 install:
     - sudo apt-get update > /dev/null
     - sudo apt-get build-dep smuxi > /dev/null