Explicitly choose Mono 4.0.5

dougbu · dougbu · commit cbbddda8de95 · 2015-11-17T10:51:01.000-08:00
- avoids future problems related to aspnet/External#48
  - e.g. when Travis updates default Mono version in `csharp` bundle
diff --git a/.travis.yml b/.travis.yml
@@ -1,4 +1,6 @@
 language: csharp
 sudo: false
+mono:
+  - 4.0.5
 script:
   - ./build.sh --quiet verify
