Merge pull request #159 from apollostack/origin/fix-union-typedef

Union type definition must be lower case

Author: leebyron

spec/Section 3 -- Type System.md

@@ -653,7 +653,7 @@ typed fragments.
 For example, we might have the following type system:
 
 ```
-Union SearchResult = Photo | Person
+union SearchResult = Photo | Person
 
 type Person {
   name: String