Depreate functions that spawn a thread (#2418)

* Depreate functions that spawn a thread

* Bump versions

substrate/core/consensus/slots/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "substrate-consensus-slots"
-version = "1.0.0"
+version = "1.1.0"
 authors = ["Parity Technologies <admin@parity.io>"]
 description = "Generic slots-based utilities for consensus"
 edition = "2018"

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

@@ -71,6 +71,7 @@ pub fn inherent_to_common_error(err: inherents::RuntimeString) -> consensus_comm
 }
 
 /// Start a new slot worker in a separate thread.
+#[deprecated(since = "1.1", note = "Please spawn a thread manually")]
 pub fn start_slot_worker_thread<B, C, W, SO, SC, T, OnExit>(
 	slot_duration: SlotDuration<T>,
 	client: Arc<C>,