Merge pull request #771 from terenc3t/patch-55

Fix validator toc links

Author: djrtwo

specs/validator/0_beacon-chain-validator.md

@@ -40,11 +40,11 @@ __NOTICE__: This document is a work-in-progress for researchers and implementers
                 - [Slot](#slot-1)
                 - [Shard](#shard)
                 - [Beacon block root](#beacon-block-root)
-                - [Epoch boundary root](#epoch-boundary-root)
+                - [Target root](#target-root)
                 - [Crosslink data root](#crosslink-data-root)
                 - [Latest crosslink](#latest-crosslink)
-                - [Justified epoch](#justified-epoch)
-                - [Justified block root](#justified-block-root)
+                - [Source epoch](#source-epoch)
+                - [Source root](#source-root)
             - [Construct attestation](#construct-attestation)
                 - [Data](#data)
                 - [Aggregation bitfield](#aggregation-bitfield)