remove dead code in rustc version

Author: jyn514

src/utils/rustc_version.rs

@@ -1,5 +1,4 @@
 
-use std::process::{Command, Output};
 use regex::Regex;
 use error::Result;
 use failure::err_msg;
@@ -18,26 +17,6 @@ pub fn parse_rustc_version<S: AsRef<str>>(version: S) -> Result<String> {
             captures.get(2).unwrap().as_str()))
 }
 
-
-/// Returns current version of rustc and cratesfyi
-pub fn get_current_versions() -> Result<(String, String)> {
-    let rustc_version = command_result(Command::new("rustc").arg("--version").output()?)?;
-    let cratesfyi_version = command_result(Command::new("rustc").arg("--version").output()?)?;
-
-    Ok((rustc_version, cratesfyi_version))
-}
-
-
-pub fn command_result(output: Output) -> Result<String> {
-    let mut command_out = String::from_utf8_lossy(&output.stdout).into_owned();
-    command_out.push_str(&String::from_utf8_lossy(&output.stderr).into_owned()[..]);
-    match output.status.success() {
-        true => Ok(command_out),
-        false => Err(err_msg(command_out)),
-    }
-}
-
-
 #[test]
 fn test_parse_rustc_version() {
     assert_eq!(parse_rustc_version("rustc 1.10.0-nightly (57ef01513 2016-05-23)").unwrap(),