diff --git a/Cargo.toml b/Cargo.toml
index 2b248d4..9fe4743 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,6 +2,7 @@
 name = "benchmark_repository"
 version = "0.1.0"
 authors = ["Patrick Lühne <patrick@luehne.de>"]
+edition = "2018"
 
 [dependencies]
 git2 = "^0.7"
@@ -14,4 +15,4 @@ yaml-rust = "0.4"
 
 [dependencies.cpython]
 git = "https://github.com/dgrunwald/rust-cpython/"
-branch = "master"
+branch = "master"
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index 7a97934..0471d64 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,17 +1,10 @@
-extern crate git2;
-extern crate pretty_env_logger;
-#[macro_use]
-extern crate log;
-extern crate indicatif;
-extern crate tempfile;
-extern crate walkdir;
-
 use git2::{Cred, Error, FetchOptions, Index, IndexEntry, IndexTime, Oid, Progress, PushOptions, RemoteCallbacks, Repository, Signature};
+use indicatif::{ProgressBar, ProgressStyle};
+use log::{info, trace};
 use std::path::{Path, PathBuf};
 use std::string::String;
 use std::str;
 use std::sync::Arc;
-use indicatif::{ProgressBar, ProgressStyle};
 use walkdir::WalkDir;
 
 pub struct BenchmarkRepositoryInner