Some user properties are optional; msuchane#4

Author: Marek Suchánek

src/issue_model.rs

@@ -104,8 +104,8 @@ pub struct User {
     pub display_name: String,
     #[serde(rename = "emailAddress")]
     pub email_address: Option<String>,
-    pub key: String,
-    pub name: String,
+    pub key: Option<String>,
+    pub name: Option<String>,
     #[serde(rename = "timeZone")]
     pub time_zone: String,
     #[serde(rename = "avatarUrls")]
@@ -114,6 +114,8 @@ pub struct User {
     pub self_link: String,
     #[serde(flatten)]
     pub extra: Value,
+    #[serde(rename = "accountId")]
+    pub account_id: Option<String>,
 }
 
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