Get message endpoint (#14)

Reviewed-on: phoenix/textsender_api#14

src/caller/mod.rs

@@ -12,6 +12,8 @@ pub mod endpoints {
     pub const UPDATE_CONTACT_NAME: &str = "/api/v1/contact/update";
     /// Constant for adding message endpoint
     pub const ADD_MESSAGE: &str = "/api/v1/message/new";
+    /// Constant for getting messages endpoint
+    pub const GET_MESSAGE: &str = "/api/v1/message";
 }
 
 pub mod response {