Rename db crate to store

beacon_node/network/src/beacon_chain.rs

@@ -1,9 +1,9 @@
 use beacon_chain::BeaconChain as RawBeaconChain;
 use beacon_chain::{
-    db::Store,
     fork_choice::ForkChoice,
     parking_lot::RwLockReadGuard,
     slot_clock::SlotClock,
+    store::Store,
     types::{BeaconState, ChainSpec},
     AttestationValidationError, CheckPoint,
 };