remove msbuild dep

Author: Eirik Tsarpalis

.travis.yml

@@ -1,10 +1,5 @@
 language: csharp
 
-addons:
-  apt:
-    packages:
-       - msbuild
-
 matrix:
   include:
     - os: linux # Ubuntu 14.04
@@ -25,4 +20,4 @@ script:
 
 branches:
   except:
-    - gh-pages
+    - gh-pages