Signed transactions now have affinity with runtime versions (#3430)

* Signed transactions now has affinity with runtime versions

* Bump runtime version

substrate/srml/example/src/lib.rs

@@ -544,6 +544,7 @@ mod tests {
 		type MaximumBlockWeight = MaximumBlockWeight;
 		type MaximumBlockLength = MaximumBlockLength;
 		type AvailableBlockRatio = AvailableBlockRatio;
+		type Version = ();
 	}
 	parameter_types! {
 		pub const ExistentialDeposit: u64 = 0;