Remove nightly features

Author: Empty2k12

src/client/mod.rs

@@ -151,8 +151,7 @@ impl InfluxDbClient {
                 })
                 .and_then(|body| {
                     if let Ok(utf8) = std::str::from_utf8(&body) {
-                        let mut s = String::new();
-                        utf8.clone_into(&mut s);
+                        let s = utf8.to_owned();
 
                         // todo: improve error parsing without serde
                         if s.contains("\"error\"") {

src/lib.rs

@@ -1,5 +1,4 @@
 #![allow(dead_code)]
-#![feature(toowned_clone_into)]
 
 #[macro_use]
 extern crate failure;