Simplify deposit_event declaration in decl_module (#3506)

* simplify module deposit_event declaration

* fix

* bump version

* fix

* fix test

* fix doc

substrate/node-template/runtime/src/template.rs

@@ -35,7 +35,7 @@ decl_module! {
 	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
 		// Initializing events
 		// this is needed only if you are using events in your module
-		fn deposit_event<T>() = default;
+		fn deposit_event() = default;
 
 		// Just a dummy entry point.
 		// function that can be called by the external world as an extrinsics call