move to include_str!() macro for all data

Move away from I/O to just including the data in the program via macro.

src/day03.rs

@@ -1,4 +1,3 @@
-use crate::utils::read_file;
 use anyhow::Result;
 
 fn strings_to_ints(s: &str) -> Vec<usize> {
@@ -89,7 +88,7 @@ fn diagnose_lifesupport(s: &str) -> usize {
 }
 
 pub(crate) fn run() -> Result<(usize, usize)> {
-    let input = read_file("data/day03.txt")?;
+    let input = include_str!("../data/day03.txt");
     Ok((diagnose_power(&input), diagnose_lifesupport(&input)))
 }
 
@@ -99,14 +98,14 @@ mod tests {
 
     #[test]
     fn test_example() {
-        let input = read_file("data/day03-test.txt").unwrap();
+        let input = include_str!("../data/day03-test.txt");
         assert_eq!(diagnose_power(&input), 198);
         assert_eq!(diagnose_lifesupport(&input), 230);
     }
 
     #[test]
     fn test_my_data() {
-        let input = read_file("data/day03.txt").unwrap();
+        let input = include_str!("../data/day03.txt");
         assert_eq!(diagnose_power(&input), 4191876);
         // assert_eq!(follow_course(&input), 2070300);
         // assert_eq!(follow_course_better(&input), 2078985210);