Fix travis build.

Cory Thompson · Cory Thompson · commit 2541ab362e8c · 2018-02-10T10:44:44.000+11:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,7 +1,7 @@
 language: csharp
 dist: trusty
 mono: none
-dotnet: 1.0.1
+dotnet: 1.0.9
 
 install:
   - dotnet restore
