message: Better use of default
diff: @@ -21,7 +21,7 @@ pub fn mock_dependencies(
  ) -> Extern<MockStorage, MockApi, MockQuerier> {
  let contract_addr = HumanAddr::from(CONTRACT_ADDR);
  Extern {
  - storage: MockStorage::new(),
  + storage: MockStorage::default(),
  api: MockApi::new(canonical_length),
  querier: MockQuerier::new(&[(&contract_addr, contract_balance)]),
  }
  @@ -34,7 +34,7 @@ pub fn mock_dependencies_with_balances(
  balances: &[(&HumanAddr, &[Coin])],
  ) -> Extern<MockStorage, MockApi, MockQuerier> {
  Extern {
  - storage: MockStorage::new(),
  + storage: MockStorage::default(),
  api: MockApi::new(canonical_length),
  querier: MockQuerier::new(balances),
  }
  @@ -124,7 +124,7 @@ pub fn mock_env<T: Api, U: Into<HumanAddr>>(api: &T, sender: U, sent: &[Coin]) -
  /// MockQuerier holds an immutable table of bank balances
  /// TODO: also allow querying contracts
  -#[derive(Clone)]
  +#[derive(Clone, Default)]
  pub struct MockQuerier {
  bank: BankQuerier,
  #[cfg(feature = "staking")]
  @@ -143,7 +143,7 @@ impl MockQuerier {
  pub fn new(balances: &[(&HumanAddr, &[Coin])]) -> Self {
  MockQuerier {
  bank: BankQuerier::new(balances),
  - staking: staking::StakingQuerier::new(&[], &[]),
  + staking: staking::StakingQuerier::default(),
  }
  }
  @@ -175,7 +175,7 @@ impl Querier for MockQuerier {
  }
  }
  -#[derive(Clone)]
  +#[derive(Clone, Default)]
  struct BankQuerier {
  balances: HashMap<HumanAddr, Vec<Coin>>,
  }
  @@ -225,7 +225,7 @@ mod staking {
  use crate::serde::to_binary;
  use crate::traits::QuerierResult;
  - #[derive(Clone)]
  + #[derive(Clone, Default)]
  pub struct StakingQuerier {
  validators: Vec<Validator>,
  delegations: Vec<Delegation>,
  