adding csharp tests to travis
diff --git a/.travis.yml b/.travis.yml
index 7d86345..f1839ac 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,13 +2,19 @@
 before_install:
   - sudo add-apt-repository ppa:yjwong/gflags -y
   - sudo add-apt-repository ppa:h-rayflood/llvm -y
+  - sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 3FA7E0328081BFF6A14DA29AA6A19B38D3D831EF
+  - echo "deb http://download.mono-project.com/repo/debian wheezy main" | sudo tee /etc/apt/sources.list.d/mono-xamarin.list
+  - echo "deb http://download.mono-project.com/repo/debian wheezy-libtiff-compat main" | sudo tee -a /etc/apt/sources.list.d/mono-xamarin.list
   - sudo apt-get update -qq
   - sudo apt-get install -qq libgtest-dev libgflags-dev python-virtualenv clang-3.5
   - sudo pip install cpp-coveralls mako simplejson
+  - sudo apt-get install -qq mono-devel nunit
+  - wget www.nuget.org/NuGet.exe -O nuget.exe
 env:
   global:
     - RUBY_VERSION=2.1
     - COVERALLS_PARALLEL=true
+    - NUGET="mono nuget.exe"
   matrix:
     - CONFIG=opt TEST=sanity
     - CONFIG=dbg TEST=c
@@ -18,6 +24,7 @@
     - CONFIG=opt TEST=node
     - CONFIG=opt TEST=ruby
     - CONFIG=opt TEST=python
+    - CONFIG=opt TEST=csharp
     - CONFIG=gcov TEST=c
     - CONFIG=gcov TEST=c++
     - USE_GCC=4.4 CONFIG=opt TEST=build