normalize new lines in tests (\r\n) (#62)

Normalize the new lines for the snapshots, so when you run
```bash
cargo insta test
```

All passes as green ✅

This should also allow us to enable Windows in the CI tests, but we
don't need to do it

Author: AucaCoyan

.gitattributes

@@ -0,0 +1 @@
+* text=auto eol=lf

src/test.rs

@@ -8,14 +8,17 @@ use std::path::Path;
 
 fn evaluate_example(fname: &Path) -> String {
     let mut compiler = Compiler::new();
-    let contents = std::fs::read(fname).expect("We only run tests found by glob");
+    let contents = std::fs::read_to_string(fname).expect("We only run tests found by glob");
+    // normalize newlines
+    let replaced = contents.replace("\r\n", "\n");
+    let contents = replaced.as_bytes();
 
     let span_offset = compiler.span_offset();
-    compiler.add_file(&fname.to_string_lossy(), &contents);
+    compiler.add_file(&fname.to_string_lossy(), contents);
 
-    let (tokens, err) = lex(&contents, span_offset);
+    let (tokens, err) = lex(contents, span_offset);
     if let Err(e) = err {
-        tokens.eprint(&contents);
+        tokens.eprint(contents);
         eprintln!("Lexing error. Error: {:?}", e);
         std::process::exit(1);
     }
@@ -53,14 +56,13 @@ fn evaluate_example(fname: &Path) -> String {
 }
 
 fn evaluate_lexer(fname: &Path) -> String {
-    let contents = std::fs::read(fname);
+    let contents = std::fs::read_to_string(fname).expect("We only run tests found by glob");
+    // normalize newlines
+    let replaced = contents.replace("\r\n", "\n");
+    let contents = replaced.as_bytes();
 
-    let Ok(contents) = contents else {
-        panic!("Lexer: can't find file {}", fname.to_string_lossy());
-    };
-
-    let (tokens, err) = lex(&contents, 0);
-    let mut res = tokens.display(&contents);
+    let (tokens, err) = lex(contents, 0);
+    let mut res = tokens.display(contents);
 
     if let Err(e) = err {
         res.push_str(&format!("Lexing error. Error: {:?}", e));