fix whitespace

2020/day_1/src/main.rs

@@ -1,5 +1,5 @@
 fn main() {
-    let mut v: Vec<i32> = Vec::new();
+   let mut v: Vec<i32> = Vec::new();
     let contents = std::fs::read_to_string("input1").unwrap();
     for s in contents.lines() {
         v.push(s.parse::<i32>().unwrap());