Let Rojo pull auth cookie from registry on Windows

src/commands/upload.rs

@@ -2,20 +2,27 @@ use std::path::PathBuf;
 
 use failure::Fail;
 
+use crate::auth_cookie::get_auth_cookie;
+
 #[derive(Debug, Fail)]
 pub enum UploadError {
-    #[fail(display = "This error cannot happen")]
-    StubError,
+    #[fail(display = "Rojo could not find your Roblox auth cookie. Please pass one via --cookie.")]
+    NeedAuthCookie,
 }
 
 #[derive(Debug)]
 pub struct UploadOptions<'a> {
     pub fuzzy_project_path: PathBuf,
-    pub security_cookie: Option<String>,
+    pub auth_cookie: Option<String>,
     pub asset_id: u64,
     pub kind: Option<&'a str>,
 }
 
-pub fn upload(_options: &UploadOptions) -> Result<(), UploadError> {
+pub fn upload(options: UploadOptions) -> Result<(), UploadError> {
+    let cookie = options
+        .auth_cookie
+        .or_else(get_auth_cookie)
+        .ok_or(UploadError::NeedAuthCookie)?;
+
     unimplemented!("TODO: Reimplement upload command");
 }