Fix warnings (#225)

src/encoder/compression/deflate.rs

@@ -1,6 +1,5 @@
-use crate::{encoder::compression::*, tags::CompressionMethod};
+use crate::encoder::compression::*;
 use flate2::{write::ZlibEncoder, Compression as FlateCompression};
-use std::io::Write;
 
 /// The Deflate algorithm used to compress image data in TIFF files.
 #[derive(Debug, Clone, Copy)]