Merge branch 'dbrgn-ascii-ext-import'

.travis.yml

@@ -2,6 +2,7 @@ language: rust
 
 rust:
     - stable
+    - 1.20.0
 
 sudo: false
 

src/write.rs

@@ -19,6 +19,8 @@ use msdos_time::TmMsDosExt;
 use bzip2;
 #[cfg(feature = "bzip2")]
 use bzip2::write::BzEncoder;
+#[allow(unused_imports)] // Rust <1.23 compat
+use std::ascii::AsciiExt;
 
 enum GenericZipWriter<W: Write + io::Seek>
 {