added classbook edit endpoint and save absence request

src/class_book/class_book_save_absence_request.rs

@@ -0,0 +1,3 @@
+pub struct ClassBookSaveAbsenceRequest {
+  //TODO
+}

src/class_book/endpoints.rs

@@ -0,0 +1,9 @@
+use crate::{ClassBookSaveAbsenceRequest, ContentType, Endpoint};
+use std::marker::PhantomData;
+
+pub const EDIT_CLASSBOOK_ENDPOINT: Endpoint<(), ClassBookSaveAbsenceRequest> = Endpoint::Post {
+    url: "/api/3/classbook/{recordId}",
+    auth: true,
+    content_type: ContentType::Json,
+    _types: PhantomData,
+};

src/class_book/mod.rs

@@ -0,0 +1,5 @@
+mod endpoints;
+mod class_book_save_absence_request;
+
+pub use class_book_save_absence_request::*;
+pub use endpoints::*;

src/lib.rs

@@ -15,11 +15,13 @@ mod teaching;
 mod timetable;
 mod user;
 mod webmodules;
+mod class_book;
 //campaign
 //marking
 //komens
 //predictor
 
+pub use class_book::*;
 pub use absence::*;
 pub use auth::*;
 pub use endpoints::*;