Get schedule message endpoint (#16)

Reviewed-on: phoenix/textsender_api#16

src/caller/mod.rs

@@ -16,6 +16,8 @@ pub mod endpoints {
     pub const GET_MESSAGE: &str = "/api/v1/message";
     /// Constant for scheduling message endpoint
     pub const SCHEDULE_MESSAGE: &str = "/api/v1/schedule/message";
+    /// Constant for getting scheduled message endpoint
+    pub const GET_SCHEDULE_MESSAGE: &str = "/api/v1/schedule/message";
 }
 
 pub mod response {