deps update; added ERC20Upgradeable

Author: kostysh

README.md

@@ -13,8 +13,8 @@ npm i @windingtree/smart-contracts-libraries
 import "@windingtree/smart-contracts-libraries/contracts/ERC165/ERC165Removable.sol";
 ```
 
-## Contracts
+## Contracts and libraries
 
-- ERC165Removable
-
-> OpenZeppelin's ERC165 contract extended with interfaces removing feature
+- [ERC165Removable.sol](contracts/ERC165/ERC165Removable.sol): OpenZeppelin's ERC165 contract extended with interfaces removing feature
+- [ERC20Configurable.sol](contracts/ERC20/ERC20Configurable.sol): Easy configurable token
+- [ERC20Upgradeable.sol](contracts/ERC20/ERC20Upgradeable.sol): Easy configurable and upgradeable token

contracts/ERC20/ERC20Configurable.sol

@@ -1,14 +1,15 @@
 // SPDX-License-Identifier: MIT
 
+// SPDX-License-Identifier: MIT
+
 pragma solidity ^0.6.0;
 
-import "@openzeppelin/contracts/GSN/Context.sol";
 import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 
 /**
  * @dev Easy configurable token
  */
-contract ERC20Configurable is Context, ERC20 {
+contract ERC20Configurable is ERC20 {
 
     /// @dev Token constructor
     constructor(

contracts/ERC20/ERC20Upgradeable.sol

@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.6.0;
+
+import "@openzeppelin/upgrades-core/contracts/Initializable.sol";
+import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
+
+/**
+ * @dev Easy configurable and upgradeable token
+ */
+contract ERC20Upgradeable is Initializable, ERC20 {
+
+    /// @dev Token constructor
+    initialize(
+      string memory name,
+      string memory symbol,
+      uint8 decimals,
+      uint256 supply
+    ) public initializer {
+        _name = name;
+        _symbol = symbol;
+        _setupDecimals(decimals);
+        _mint(msg.sender, supply);
+    }
+}