Implement support for renaming runtime api functions (#2160)

* Implement support for renaming runtime api functions

* Redelete the wasm files

* FIxes test

* Fix test correctly...

* Bring back old `authorities`

* Tag as deprecated

* Fixes compilation on WASM

* Add missing method implementations

* Fixes tests

* Increase `spec_version`

substrate/core/client/src/runtime_api.rs

@@ -35,6 +35,7 @@ pub use runtime_version::{ApiId, RuntimeVersion, ApisVec, create_apis_vec};
 pub use rstd::{slice, mem};
 #[cfg(feature = "std")]
 use rstd::result;
+#[doc(hidden)]
 pub use parity_codec::{Encode, Decode};
 #[cfg(feature = "std")]
 use crate::error;
@@ -42,6 +43,7 @@ use sr_api_macros::decl_runtime_apis;
 use primitives::OpaqueMetadata;
 #[cfg(feature = "std")]
 use std::panic::UnwindSafe;
+use rstd::vec::Vec;
 
 /// Something that can be constructed to a runtime api.
 #[cfg(feature = "std")]
@@ -113,13 +115,18 @@ pub trait CallRuntimeAt<Block: BlockT> {
 decl_runtime_apis! {
 	/// The `Core` api trait that is mandatory for each runtime.
 	#[core_trait]
+	#[api_version(2)]
 	pub trait Core {
 		/// Returns the version of the runtime.
 		fn version() -> RuntimeVersion;
 		/// Execute the given block.
 		fn execute_block(block: Block);
 		/// Initialize a block with the given header.
+		#[renamed("initialise_block", 2)]
 		fn initialize_block(header: &<Block as BlockT>::Header);
+		/// Returns the authorities.
+		#[deprecated(since = "1.0", note = "Please switch to `AuthoritiesApi`.")]
+		fn authorities() -> Vec<AuthorityIdFor<Block>>;
 	}
 
 	/// The `Metadata` api trait that returns metadata for the runtime.