Fix Travis-CI.

- Added platform specific path handling to the TagHelperUsageDescriptorFactoryTests.

.travis.yml

@@ -1,6 +1,6 @@
 language: csharp
 sudo: false
 mono:
-  - 3.12.0
+  - alpha
 script:
   - ./build.sh --quiet verify

test/Microsoft.AspNet.Razor.Runtime.Test/TagHelpers/TagHelperUsageDescriptorFactoryTest.cs

@@ -31,11 +31,14 @@ namespace Microsoft.AspNet.Razor.Runtime.TagHelpers
         // These test assemblies don't really exist. They are used to look up corresponding XML for a fake assembly
         // which is based on the DocumentedTagHelper type.
         public static readonly string DocumentedAssemblyLocation =
-            Directory.GetCurrentDirectory() + "/TestFiles/NotLocalized/TagHelperDocumentation.dll";
+            Directory.GetCurrentDirectory() +
+            string.Format("{0}TestFiles{0}NotLocalized{0}TagHelperDocumentation.dll", Path.DirectorySeparatorChar);
         public static readonly string LocalizedDocumentedAssemblyLocation =
-            Directory.GetCurrentDirectory() + "/TestFiles/Localized/TagHelperDocumentation.dll";
+            Directory.GetCurrentDirectory() +
+            string.Format("{0}TestFiles{0}Localized{0}TagHelperDocumentation.dll", Path.DirectorySeparatorChar);
         public static readonly string DocumentedAssemblyCodeBase =
-            "file:///" + DocumentedAssemblyLocation;
+            "file:" + new string(Path.DirectorySeparatorChar, 3) +
+            DocumentedAssemblyLocation.TrimStart(Path.DirectorySeparatorChar);
 
         public static TheoryData CreateDescriptor_TypeDocumentationData
         {