Add mas support for macOS (fix #307)

src/steps/os/macos.rs

@@ -1,9 +1,17 @@
 use crate::executor::RunType;
 use crate::terminal::print_separator;
+use crate::utils::require;
 use anyhow::Result;
 
+pub fn run_mas(run_type: RunType) -> Result<()> {
+    let mas = require("mas")?;
+    print_separator("macOS App Store");
+
+    run_type.execute(mas).arg("upgrade").check_run()
+}
+
 pub fn upgrade_macos(run_type: RunType) -> Result<()> {
-    print_separator("App Store");
+    print_separator("macOS system update");
 
     run_type
         .execute("softwareupdate")