Added the signature for passing filters into the render function.

Added the signature for passing filters into the render function but I am not yet using the filters.

src/bin.rs

@@ -1,5 +1,6 @@
 extern crate nom;
 
+use parser::Filter;
 use renderer::compile_template;
 use renderer::CompiledTemplate;
 use renderer::ContextElement;
@@ -73,15 +74,16 @@ fn read_context_from_stdin() -> serde_json::Value {
 impl ContextElement for serde_json::Value {}
 
 impl Renderable for serde_json::Value {
-    fn render(&self) -> Result<String, RenderError> {
+    fn render(&self, filters: &Vec<Filter>) -> Result<String, RenderError> {
         match self {
             serde_json::Value::Null => Ok("".to_owned()),
             serde_json::Value::Bool(boolean) => Ok(boolean.to_string()),
             serde_json::Value::Number(num) => Ok(num.to_string()),
             serde_json::Value::String(string) => Ok(string.to_string()),
             serde_json::Value::Array(arr) => {
+                // TODO: Handle the filters instead of passing a Vec::new()
                 let rendered: Result<Vec<String>, RenderError> =
-                    arr.iter().map(|val| val.render()).collect();
+                    arr.iter().map(|val| val.render(&Vec::new())).collect();
                 let rendered_slice: &[String] = &rendered?;
                 Ok(rendered_slice.join(","))
             }