Cleanup imports and require Rust 1.15.

README

@@ -22,7 +22,7 @@ Usage
 Dependencies
 ------------
 
-   Rust 1.12 or later is required to build.
+   Rust 1.15 or later is required to build.
 
 Specifications
 --------------

src/jpeg.rs

@@ -109,7 +109,6 @@ pub fn is_jpeg(buf: &[u8]) -> bool {
 #[cfg(test)]
 mod tests {
     use std::io::Cursor;
-    use error::Error;
     use super::*;
 
     #[test]

src/reader.rs

@@ -105,7 +105,6 @@ impl Reader {
 #[cfg(test)]
 mod tests {
     use std::io::BufReader;
-    use tiff::Field;
     use value::Value;
     use super::*;
 

src/tiff.rs

@@ -192,7 +192,6 @@ impl DateTime {
 
 #[cfg(test)]
 mod tests {
-    use error::Error;
     use super::*;
 
     // Before the error is returned, the IFD is parsed twice as the

src/value.rs

@@ -263,7 +263,6 @@ fn parse_unknown<'a>(data: &'a [u8], offset: usize, count: usize)
 mod tests {
     use endian::BigEndian;
     use super::*;
-    use super::parse_short;
 
     #[test]
     fn byte() {