message: Fix test_latest_versions
  latest_version function is now taking &Vec<String> instead of Json
  because of versions used in CrateDetails.
diff: @@ -471,18 +471,13 @@ mod test {
  #[test]
  fn test_latest_version() {
  - let json = r#"
  - [
  - "1.0.0",
  - "1.1.0",
  - "0.9.0",
  - "0.9.1"
  - ]
  - "#;
  - let json = Json::from_str(json).unwrap();
  - assert_eq!(latest_version(&json, "1.1.0"), None);
  - assert_eq!(latest_version(&json, "1.0.0"), Some("1.1.0".to_owned()));
  - assert_eq!(latest_version(&json, "0.9.0"), Some("1.1.0".to_owned()));
  - assert_eq!(latest_version(&json, "invalidversion"), None);
  + let versions = vec!["1.0.0".to_string(),
  + "1.1.0".to_string(),
  + "0.9.0".to_string(),
  + "0.9.1".to_string()];
  + assert_eq!(latest_version(&versions, "1.1.0"), None);
  + assert_eq!(latest_version(&versions, "1.0.0"), Some("1.1.0".to_owned()));
  + assert_eq!(latest_version(&versions, "0.9.0"), Some("1.1.0".to_owned()));
  + assert_eq!(latest_version(&versions, "invalidversion"), None);
  }
  }
  