use string for status id in StatusBuilder

src/registration.rs

@@ -284,12 +284,9 @@ impl<H: HttpSend> Registered<H> {
     /// provided by the authorisation url.
     pub fn complete(&self, code: &str) -> Result<Mastodon<H>> {
         let url = format!(
-            "{}/oauth/token?client_id={}&client_secret={}&code={}&grant_type=authorization_code&redirect_uri={}",
-            self.base,
-            self.client_id,
-            self.client_secret,
-            code,
-            self.redirect
+            "{}/oauth/token?client_id={}&client_secret={}&code={}&grant_type=authorization_code&\
+             redirect_uri={}",
+            self.base, self.client_id, self.client_secret, code, self.redirect
         );
 
         let token: AccessToken = self.send(self.client.post(&url))?.json()?;

src/status_builder.rs

@@ -21,9 +21,9 @@ use std::fmt;
 pub struct StatusBuilder {
     /// The text of the status.
     pub status: String,
-    /// Ids of accounts being replied to.
+    /// Id of status being replied to.
     #[serde(skip_serializing_if = "Option::is_none")]
-    pub in_reply_to_id: Option<u64>,
+    pub in_reply_to_id: Option<String>,
     /// Ids of media attachments being attached to the status.
     #[serde(skip_serializing_if = "Option::is_none")]
     pub media_ids: Option<Vec<String>>,