Bump solhint from 2.1.0 to 2.3.0 (#1936)

* Bump solhint from 2.1.0 to 2.3.0

Bumps [solhint](https://github.com/protofire/solhint) from 2.1.0 to 2.3.0.
- [Release notes](https://github.com/protofire/solhint/releases)
- [Changelog](https://github.com/protofire/solhint/blob/master/CHANGELOG.md)
- [Commits](https://github.com/protofire/solhint/commits)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

* Fix linter

contracts/token/ERC777/ERC777.sol

@@ -28,7 +28,7 @@ contract ERC777 is Context, IERC777, IERC20 {
     using SafeMath for uint256;
     using Address for address;
 
-    IERC1820Registry constant private _erc1820 = IERC1820Registry(0x1820a4B7618BdE71Dce8cdc73aAB6C95905faD24);
+    IERC1820Registry constant private ERC1820_REGISTRY = IERC1820Registry(0x1820a4B7618BdE71Dce8cdc73aAB6C95905faD24);
 
     mapping(address => uint256) private _balances;
 
@@ -78,8 +78,8 @@ contract ERC777 is Context, IERC777, IERC20 {
         }
 
         // register interfaces
-        _erc1820.setInterfaceImplementer(address(this), keccak256("ERC777Token"), address(this));
-        _erc1820.setInterfaceImplementer(address(this), keccak256("ERC20Token"), address(this));
+        ERC1820_REGISTRY.setInterfaceImplementer(address(this), keccak256("ERC777Token"), address(this));
+        ERC1820_REGISTRY.setInterfaceImplementer(address(this), keccak256("ERC20Token"), address(this));
     }
 
     /**
@@ -437,7 +437,7 @@ contract ERC777 is Context, IERC777, IERC20 {
     )
         private
     {
-        address implementer = _erc1820.getInterfaceImplementer(from, TOKENS_SENDER_INTERFACE_HASH);
+        address implementer = ERC1820_REGISTRY.getInterfaceImplementer(from, TOKENS_SENDER_INTERFACE_HASH);
         if (implementer != address(0)) {
             IERC777Sender(implementer).tokensToSend(operator, from, to, amount, userData, operatorData);
         }
@@ -465,7 +465,7 @@ contract ERC777 is Context, IERC777, IERC20 {
     )
         private
     {
-        address implementer = _erc1820.getInterfaceImplementer(to, TOKENS_RECIPIENT_INTERFACE_HASH);
+        address implementer = ERC1820_REGISTRY.getInterfaceImplementer(to, TOKENS_RECIPIENT_INTERFACE_HASH);
         if (implementer != address(0)) {
             IERC777Recipient(implementer).tokensReceived(operator, from, to, amount, userData, operatorData);
         } else if (requireReceptionAck) {

package.json

@@ -63,7 +63,7 @@
     "micromatch": "^4.0.2",
     "nodemon": "^1.19.3",
     "openzeppelin-test-helpers": "^0.4.3",
-    "solhint": "2.1.0",
+    "solhint": "2.3.0",
     "solidity-coverage": "github:rotcivegaf/solidity-coverage#5875f5b7bc74d447f3312c9c0e9fc7814b482477",
     "solidity-docgen": "^0.3.4",
     "truffle": "^5.0.39"