Remove availability statement (#79)

* remove availability vote type from statement-table

* expunge availability statement from consensus module

* expunge availability from duty roster

* rename StatementProducer to ParachainWork

* fix runtime tests and remove availability statement variant

* update wasm

polkadot/primitives/src/parachain.rs

@@ -64,9 +64,6 @@ pub enum Chain {
 pub struct DutyRoster {
 	/// Lookup from validator index to chain on which that validator has a duty to validate.
 	pub validator_duty: Vec<Chain>,
-	/// Lookup from validator index to chain on which that validator has a duty to guarantee
-	/// availability.
-	pub guarantor_duty: Vec<Chain>,
 }
 
 /// Extrinsic data for a parachain.
@@ -206,9 +203,6 @@ pub enum Statement {
 	/// State a candidate is invalid.
 	#[codec(index = "3")]
 	Invalid(Hash),
-	/// State a candidate's associated data is unavailable.
-	#[codec(index = "4")]
-	Available(Hash),
 }
 
 /// An either implicit or explicit attestation to the validity of a parachain
@@ -234,8 +228,6 @@ pub struct AttestedCandidate {
 	pub candidate: CandidateReceipt,
 	/// Validity attestations.
 	pub validity_votes: Vec<(SessionKey, ValidityAttestation)>,
-	/// Availability attestations.
-	pub availability_votes: Vec<(SessionKey, CandidateSignature)>,
 }
 
 impl AttestedCandidate {