Merge pull request #211 from baileywickham/master

Added warning for capital field names in structs

examples/json/json.go

@@ -14,6 +14,8 @@ type response1 struct {
 	Page   int
 	Fruits []string
 }
+// Only exported fields will be encoded/decoded in JSON. 
+// Fields must start with capital letters to be exported.
 type response2 struct {
 	Page   int      `json:"page"`
 	Fruits []string `json:"fruits"`