Build: Use Travis CI language support for .NET

.travis.yml

@@ -1,12 +1,4 @@
-language: c
+language: csharp
-
+sudo: false
-install:
-- curl -sLo /tmp/mono.gpg http://download.mono-project.com/repo/xamarin.gpg
-- sudo apt-key add /tmp/mono.gpg
-- sudo sh -c "echo 'deb http://download.mono-project.com/repo/debian wheezy main' >> /etc/apt/sources.list.d/mono-xamarin.list"
-- sudo apt-get update -qq
-- sudo apt-get install -qq mono-complete nuget mono-vbnc fsharp libgdiplus=2.10-3
-- mozroots --import --sync --quiet
-
 script: 
-  - ./build.sh Build
+  - ./build.sh Build