cargo fix --edition and add edition="2018" to Cargo.toml.

rtiow/src/noise/lode.rs

@@ -1,8 +1,8 @@
 /// Implements the concepts from https://lodev.org/cgtutor/randomnoise.html
 use rand;
 
-use noise::NoiseSource;
-use vec3::Vec3;
+use crate::noise::NoiseSource;
+use crate::vec3::Vec3;
 
 const NOISE_SIZE: usize = 128;
 pub struct Lode {

rtiow/src/noise/mod.rs

@@ -3,7 +3,7 @@ pub mod perlin;
 
 use std::f32::consts::PI;
 
-use vec3::Vec3;
+use crate::vec3::Vec3;
 
 pub trait NoiseSource: Send + Sync {
     /// value returns noise on the interval [0., 1.).

rtiow/src/noise/perlin.rs

@@ -2,9 +2,9 @@
 #![cfg_attr(feature = "cargo-clippy", allow(many_single_char_names))]
 use rand::Rng;
 
-use noise::NoiseSource;
-use vec3::dot;
-use vec3::Vec3;
+use crate::noise::NoiseSource;
+use crate::vec3::dot;
+use crate::vec3::Vec3;
 
 pub struct Perlin {
     ran_vec: Vec<Vec3>,