AuRa fix for 1.7.x series (#7666)

* Fix Temporarily Invalid blocks handling (#7613)

* Handle temporarily invalid blocks in sync.

* Fix tests.

* Bump rustc-serialize

* Bump version.

* Update .gitlab-ci.yml

fix lint

* Remove slash from gitlab ci script to fix builds

* Start build.

sync/src/block_sync.rs

@@ -519,6 +519,10 @@ impl BlockDownloader {
 					trace!(target: "sync", "Unknown new block parent, restarting sync");
 					break;
 				},
+				Err(BlockImportError::Block(BlockError::TemporarilyInvalid(_))) => {
+					debug!(target: "sync", "Block temporarily invalid, restarting sync");
+					break;
+				},
 				Err(e) => {
 					debug!(target: "sync", "Bad block {:?} : {:?}", h, e);
 					bad = true;