Update compiler (#725)

* update compiler to recent nightly

* cargo fmt

* fix clippy

but ructe code is still complaining

* update circleci and rocket_csrf

* fix last clippy problems

* cargo fmt

* fix build issue

was caused be improper handling of recursive template (comment) by old ructe, which is fixed on newer version

build.rs

@@ -2,7 +2,7 @@ extern crate rsass;
 extern crate ructe;
 use ructe::Ructe;
 use std::process::{Command, Stdio};
-use std::{env, ffi::OsStr, fs::*, io::Write, path::*};
+use std::{ffi::OsStr, fs::*, io::Write, path::*};
 
 fn compute_static_hash() -> String {
     //"find static/ -type f ! -path 'static/media/*' | sort | xargs stat -c'%n %Y' | openssl dgst -r"