Fix deprecation warnings (#2115)

* Fix deprecation warnings

* Workaround linter bug

contracts/introspection/ERC165Checker.sol

-pragma solidity ^0.6.0;
+pragma solidity ^0.6.2;
 
 /**
  * @dev Library used to query support of an interface declared via {IERC165}.
@@ -97,7 +97,7 @@ library ERC165Checker {
         returns (bool, bool)
     {
         bytes memory encodedParams = abi.encodeWithSelector(_INTERFACE_ID_ERC165, interfaceId);
-        (bool success, bytes memory result) = account.staticcall.gas(30000)(encodedParams);
+        (bool success, bytes memory result) = account.staticcall{ gas: 30000 }(encodedParams);
         if (result.length < 32) return (false, false);
         return (success, abi.decode(result, (bool)));
     }

contracts/payment/PullPayment.sol

-pragma solidity ^0.6.0;
+pragma solidity ^0.6.2;
 
 import "./escrow/Escrow.sol";
 
@@ -62,6 +62,10 @@ contract PullPayment {
      * @param amount The amount to transfer.
      */
     function _asyncTransfer(address dest, uint256 amount) internal virtual {
-        _escrow.deposit.value(amount)(dest);
+        // solhint-disable-previous-line no-unused-vars
+
+        // TODO: remove the previous linter directive once
+        // https://github.com/protofire/solhint/issues/170 is fixed
+        _escrow.deposit{ value: amount }(dest);
     }
 }

contracts/utils/Address.sol

-pragma solidity ^0.6.0;
+pragma solidity ^0.6.2;
 
 /**
  * @dev Collection of functions related to the address type
@@ -52,7 +52,7 @@ library Address {
         require(address(this).balance >= amount, "Address: insufficient balance");
 
         // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
-        (bool success, ) = recipient.call.value(amount)("");
+        (bool success, ) = recipient.call{ value: amount }("");
         require(success, "Address: unable to send value, recipient may have reverted");
     }
 }