change simple quotes with backticks for file names

Author: Aelnor

src/cargo/ops/cargo_new.rs

@@ -478,7 +478,7 @@ pub fn init(opts: &NewOptions, config: &Config) -> CargoResult<NewProjectKind> {
             NewProjectKind::Lib.to_string()
         };
         config.shell().warn(format!(
-            "file '{}' seems to be a {} file",
+            "file `{}` seems to be a {} file",
             src_paths_types[0].relative_path, file_type
         ))?;
         src_paths_types[0].bin = has_bin

tests/testsuite/init.rs

@@ -608,7 +608,7 @@ fn creates_binary_when_instructed_and_has_lib_file_no_warning() {
         .cwd(&path)
         .with_stderr(
             "\
-[WARNING] file 'foo.rs' seems to be a library file
+[WARNING] file `foo.rs` seems to be a library file
 [CREATED] binary (application) package
 ",
         )
@@ -628,7 +628,7 @@ fn creates_library_when_instructed_and_has_bin_file() {
         .cwd(&path)
         .with_stderr(
             "\
-[WARNING] file 'foo.rs' seems to be a binary (application) file
+[WARNING] file `foo.rs` seems to be a binary (application) file
 [CREATED] library package
 ",
         )