Update quickcheck requirement from 0.6.2 to 0.7.1 (#15)

* Update quickcheck requirement from 0.6.2 to 0.7.1

Updates the requirements on [quickcheck](https://github.com/BurntSushi/quickcheck) to permit the latest version.
- [Release notes](https://github.com/BurntSushi/quickcheck/releases)
- [Commits](https://github.com/BurntSushi/quickcheck/commits/0.7.1)

Signed-off-by: dependabot[bot] <[email protected]>

* fix quickcheck tests

Signed-off-by: Yoshua Wuyts <[email protected]>

Author: dependabot[bot]

Cargo.toml

@@ -14,5 +14,6 @@ random-access-storage = "0.6.0"
 mkdirp = "0.1.0"
 
 [dev-dependencies]
-quickcheck = "0.6.2"
+quickcheck = "0.7.1"
 tempfile = "3.0.3"
+rand = "0.5.5"

tests/model.rs

@@ -1,11 +1,13 @@
 #[macro_use]
 extern crate quickcheck;
+extern crate rand;
 extern crate random_access_disk as rad;
 extern crate random_access_storage;
 extern crate tempfile;
 
 use self::Op::*;
 use quickcheck::{Arbitrary, Gen};
+use rand::Rng;
 use random_access_storage::RandomAccess;
 use std::u8;
 use tempfile::Builder;