Clean up the basic-authorship crate (#3206)

* Switch consensus-common to new futures

* Fix tests

* More tests fixing

* Make Proposer, OnSlot and SyncOracle mut

* Make the Environment mut as well

* Fix test

* Fix Babe tests

* Babe fixes

* Fix CLI service tests

* Fix Babe tests

* Remove unnecessary trait bound

* Inline the code of BlockBuilder and AuthoringApi

* Remove warning lint

* Bounds simplification

* Imports simplification

* Don't panic on bad generated block

* Code style

* Add doc example

* Remove dependency on aura

* Order dependencies alphabetically

* Minor style

substrate/core/consensus/slots/src/lib.rs

@@ -46,7 +46,7 @@ pub trait SlotWorker<B: BlockT> {
 	type OnSlot: Future<Output = Result<(), consensus_common::Error>>;
 
 	/// Called when a new slot is triggered.
-	fn on_slot(&self, chain_head: B::Header, slot_info: SlotInfo) -> Self::OnSlot;
+	fn on_slot(&mut self, chain_head: B::Header, slot_info: SlotInfo) -> Self::OnSlot;
 }
 
 /// Slot compatible inherent data.
@@ -69,8 +69,8 @@ pub trait SlotCompatible {
 pub fn start_slot_worker<B, C, W, T, SO, SC>(
 	slot_duration: SlotDuration<T>,
 	client: C,
-	worker: W,
-	sync_oracle: SO,
+	mut worker: W,
+	mut sync_oracle: SO,
 	inherent_data_providers: InherentDataProviders,
 	timestamp_extractor: SC,
 ) -> impl Future<Output = ()>