Bump to 2018 edition

This commit bumps the code to use Rust 2018.

Cargo.toml

@@ -1,15 +1,17 @@
 [package]
-name = "sparse-bitfield"
-version = "0.10.0"
-license = "MIT OR Apache-2.0"
-repository = "https://github.com/datrs/sparse-bitfield"
-documentation = "https://docs.rs/sparse-bitfield"
-description = "Bitfield that allocates a series of small buffers"
-authors = ["Yoshua Wuyts <yoshuawuyts@gmail.com>"]
-readme = "README.md"
+name = 'sparse-bitfield'
+version = '0.10.0'
+license = 'MIT OR Apache-2.0'
+repository = 'https://github.com/datrs/sparse-bitfield'
+documentation = 'https://docs.rs/sparse-bitfield'
+description = 'Bitfield that allocates a series of small buffers'
+authors = ['Yoshua Wuyts <yoshuawuyts@gmail.com>']
+readme = 'README.md'
+edition = '2018'
 
 [dependencies]
-memory-pager = "0.9.0"
+memory-pager = '0.9.0'
 
 [dev-dependencies]
-proptest = "0.9.0"
+proptest = '0.9.5'
+failure = '0.1.6'

src/lib.rs

@@ -3,13 +3,11 @@
 #![cfg_attr(nightly, doc(include = "../README.md"))]
 #![cfg_attr(test, deny(warnings))]
 
-extern crate memory_pager;
-
 mod change;
 mod iter;
 
-pub use change::Change;
-pub use iter::Iter;
+pub use crate::change::Change;
+pub use crate::iter::Iter;
 
 use memory_pager::Pager;
 use std::fs::File;

tests/model.rs

@@ -1,6 +1,4 @@
-extern crate sparse_bitfield;
-#[macro_use]
-extern crate proptest;
+use proptest::proptest;
 
 use sparse_bitfield::{Bitfield, Change};
 

tests/regression.rs

@@ -1,5 +1,3 @@
-extern crate sparse_bitfield;
-
 use sparse_bitfield::{Bitfield, Change};
 
 // src/lib.rs::is_even was incorrectly flagging 6 as odd.

tests/test.rs

@@ -1,6 +1,3 @@
-extern crate failure;
-extern crate sparse_bitfield;
-
 use failure::Error;
 use sparse_bitfield::{Bitfield, Change};
 use std::fs;