Bug 1429511 - Remove unused trait. r?jgraham
rustc warns that std::ascii::AsciiExt is not in use.
MozReview-Commit-ID: 2WKTZ5Ps2Qx
--- a/testing/mozbase/rust/mozrunner/src/runner.rs
+++ b/testing/mozbase/rust/mozrunner/src/runner.rs
@@ -1,11 +1,10 @@
use mozprofile::prefreader::PrefReaderError;
use mozprofile::profile::Profile;
-use std::ascii::AsciiExt;
use std::collections::HashMap;
use std::convert::From;
use std::env;
use std::error::Error;
use std::fmt;
use std::io::{Result as IoResult, Error as IoError, ErrorKind};
use std::path::{Path, PathBuf};
use std::process;