Successfully rendering my first template.

src/bin.rs

@@ -69,6 +69,13 @@ fn read_context_from_stdin() -> serde_json::map::Map<String, serde_json::Value>
 
 impl Renderable for serde_json::Value {
     fn render(&self) -> String {
-        self.to_string()
+        match self {
+            serde_json::Value::Null => "".to_owned(),
+            serde_json::Value::Bool(boolean) => boolean.to_string(),
+            serde_json::Value::Number(num) => num.to_string(),
+            serde_json::Value::String(string) => string.to_string(),
+            serde_json::Value::Array(_arr) => panic!("Attempted to render an array"),
+            serde_json::Value::Object(_obj) => panic!("Attempted to render an object"),
+        }
     }
 }