extracted environment variable setup into function

src/app/mod.rs

@@ -16,7 +16,7 @@ impl App {
 
     pub fn start(&self) {
         let args = args();
-        env::set_var("PATH", fs_util::docki_path_env());
+        Self::setup_environment_variables();
 
         match args.command {
             CommandArg::Build => build(),
@@ -25,6 +25,10 @@ impl App {
         }
     }
 
+    fn setup_environment_variables() {
+        env::set_var("PATH", fs_util::docki_path_env());
+    }
+
     pub fn new() -> Self {
         Self {}
     }