change tree depth to 20

.env.example

@@ -1,4 +1,4 @@
-MERKLE_TREE_HEIGHT=16
+MERKLE_TREE_HEIGHT=20
 # in wei
 ETH_AMOUNT=100000000000000000
 TOKEN_AMOUNT=100000000000000000

circuits/withdraw.circom

@@ -52,4 +52,4 @@ template Withdraw(levels) {
     }
 }
 
-component main = Withdraw(16);
+component main = Withdraw(20);