Remove sync crate, move into network crate

beacon_node/network/src/sync/mod.rs

@@ -0,0 +1,11 @@
+/// Syncing for lighthouse.
+///
+/// Stores the various syncing methods for the beacon chain.
+mod simple_sync;
+
+pub use simple_sync::SimpleSync;
+
+/// Currently implemented sync methods.
+pub enum SyncMethod {
+    SimpleSync,
+}