chore: Update INTEGRATION.md (#133)

Update INTEGRATION.md

fix typo

INTEGRATION.md

@@ -42,15 +42,15 @@ type App struct {
 
 ...
 
-// Create POA store key
+// Create PoA store key
 keys := storetypes.NewKVStoreKeys(
     ...
     poa.StoreKey,
 )
 
 ...
 
-// Initialize the PoA Keeper and and AppModule
+// Initialize the PoA Keeper and AppModule
 app.POAKeeper = poakeeper.NewKeeper(
     appCodec,
     runtime.NewKVStoreService(keys[poatypes.StoreKey]),
@@ -235,4 +235,4 @@ A future optional upgrade will grant PoA networks the ability to migrate to PoS
 
 Reasons this may be desired:
 - The chain product has been successful and the network is ready to be decentralized.
-- There is a new token use case that requires a PoS network for user delegations (ex: sharing platform rewards with stakers).
+- There is a new token use case that requires a PoS network for user delegations (ex: sharing platform rewards with stakers).