Import of Json not working

bash

$ rustup show
Default host: x86_64-unknown-linux-gnu

installed toolchains
--------------------

stable-x86_64-unknown-linux-gnu
nightly-x86_64-unknown-linux-gnu (default)

active toolchain
----------------

nightly-x86_64-unknown-linux-gnu (default)
rustc 1.21.0-nightly (2bb8fca18 2017-08-23)

main.rs

#![feature(plugin)]
#![plugin(rocket_codegen)]

#[macro_use] extern crate rocket_contrib;
extern crate rocket;
extern crate serde_json;
#[macro_use]
extern crate serde_derive;

#[cfg(test)]
mod tests;

mod static_files;

use std::io;
use std::io::Read;
use std::path::Path;

use rocket::Request;
use rocket::response::Redirect;
use rocket_contrib::{Template, Json};
use rocket::Data;
use rocket::http::RawStr;

#[derive(Serialize)]
struct TemplateContext {
    name: String,
    items: Vec<String>,
}

#[get("/")]
fn index() -> Template {
    //Redirect::to("/hello/Unknown")
    Template::render(
        "index",
        TemplateContext {
            name: "LTX2".to_string(),
            items: vec!["one".to_string()],
        },
    )
}

/// Upload a file
#[post("/upload", data = "<paste>")]
fn upload(paste: Data) -> io::Result<String> {
    let filename = format!("upload/uploaded_file.txt");
    let url = format!("{host}/uploaded_file.txt\n", host = "http://localhost:8000");
    paste.stream_to_file(Path::new(&filename))?;
    // Ok(url)
    Ok("{\"success\":true}".to_string())
}

#[error(404)]
fn not_found(req: &Request) -> Template {
    let mut map = std::collections::HashMap::new();
    map.insert("path", req.uri().as_str());
    Template::render("error/404", &map)
}

fn rocket() -> rocket::Rocket {
    rocket::ignite()
        .mount("/", routes![index, upload, static_files::all])
        // .mount("/hello", routes![upload])
        .attach(Template::fairing())
        .catch(errors![not_found])
}

fn main() {
    rocket().launch();
}

static_files.rs

use std::path::{Path, PathBuf};
use rocket::response::NamedFile;

#[get("/<path..>", rank=5)]
fn all(path: PathBuf) -> Option<NamedFile> {
    println!(">>> {:?}", Path::new("static/").join(path.clone()));
    NamedFile::open(Path::new("static/").join(path)).ok()
}