Add CW721 wrapper for ERC721 (#1264)

* Add CW721 wrapper for ERC721

* tests

Author: codchen

.gitignore

@@ -48,6 +48,7 @@ coverage.out
 # example artifacts
 example/cosmwasm/echo/target
 example/cosmwasm/cw20/target
+example/cosmwasm/cw721/target
 
 # Solidity contracts artifacts
 contracts/artifacts

example/cosmwasm/cw20/artifacts/checksums.txt

@@ -1 +1 @@
-80d19ac2966703511c136c07663280feaadb9f785570ff70da11060ab458d90f  cwerc20.wasm
+6c2094e79d3166ff3b6e25292a999cd2da47cf06dea3aea1c5b41b57d3df1805  cwerc20.wasm

example/cosmwasm/cw20/artifacts/cwerc20.wasm

@@ -15,8 +15,7 @@ pub fn instantiate(
     _info: MessageInfo,
     msg: InstantiateMsg,
 ) -> Result<Response, ContractError> {
-    let erc20_addr = deps.api.addr_validate(&msg.erc20_address)?;
-    ERC20_ADDRESS.save(deps.storage, &erc20_addr)?;
+    ERC20_ADDRESS.save(deps.storage, &msg.erc20_address)?;
     Ok(Response::default())
 }
 
@@ -48,7 +47,7 @@ pub fn execute_transfer(
 
     let querier = EvmQuerier::new(&deps.querier);
     let payload = querier.erc20_transfer_payload(recipient.clone(), amount)?;
-    let msg = EvmMsg::DelegateCallEvm { to: erc_addr.into_string(), data: payload.encoded_payload };
+    let msg = EvmMsg::DelegateCallEvm { to: erc_addr, data: payload.encoded_payload };
     let res = Response::new()
         .add_attribute("action", "transfer")
         .add_attribute("from", info.sender)

example/cosmwasm/cw20/src/contract.rs

@@ -1,4 +1,3 @@
-use cosmwasm_std::Addr;
 use cw_storage_plus::Item;
 
-pub const ERC20_ADDRESS: Item<Addr> = Item::new("erc20_address");
+pub const ERC20_ADDRESS: Item<String> = Item::new("erc20_address");