Fix incompatible serde versions, misspelled reference (#9)

src/entities/account.rs

@@ -12,7 +12,7 @@ pub struct Account {
     pub header: String,
     pub header_static: String,
     pub locked: bool,
-    pub created_at: DateTime<UTC>,
+    pub created_at: DateTime<Utc>,
     pub followers_count: u64,
     pub following_count: u64,
     pub statuses_count: u64,

src/entities/notification.rs

@@ -7,7 +7,7 @@ pub struct Notification {
     pub id: u64,
     #[serde(rename = "type")]
     pub notification_type: NotificationType,
-    pub created_at: DateTime<UTC>,
+    pub created_at: DateTime<Utc>,
     pub account: Account,
     pub status: Option<Status>,
 }

src/entities/status.rs

@@ -12,7 +12,7 @@ pub struct Status {
     pub in_reply_to_account_id: Option<u64>,
     pub reblog: Option<Box<Status>>,
     pub content: String,
-    pub created_at: DateTime<UTC>,
+    pub created_at: DateTime<Utc>,
     pub reblogs_count: u64,
     pub favourites_count: u64,
     pub reblogged: Option<bool>,