Move ERC20Votes and ERC20FlashMint out of draft (#2673)

Co-authored-by: Francisco Giordano <frangio.1@gmail.com>

CHANGELOG.md

@@ -9,6 +9,14 @@
  * Tokens: Wrap definitely safe subtractions in `unchecked` blocks. 
  * `Math`: Add a `ceilDiv` method for performing ceiling division.
 
+ ### Breaking Changes
+
+ * `ERC20FlashMint` is no longer a Draft ERC. ([#2673](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2673)))
+
+**How to update:** Change your import paths by removing the `draft-` prefix from `@openzeppelin/contracts/token/ERC20/extensions/draft-ERC20FlashMint.sol`.
+
+> See [Releases and Stability: Drafts](https://docs.openzeppelin.com/contracts/4.x/releases-stability#drafts).
+
 ## 4.1.0 (2021-04-29)
 
  * `IERC20Metadata`: add a new extended interface that includes the optional `name()`, `symbol()` and `decimals()` functions. ([#2561](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2561))

contracts/mocks/ERC3156Mock.sol → contracts/mocks/ERC20FlashMintMock.sol

@@ -3,7 +3,7 @@
 pragma solidity ^0.8.0;
 
 
-import "../token/ERC20/extensions/draft-ERC20FlashMint.sol";
+import "../token/ERC20/extensions/ERC20FlashMint.sol";
 
 contract ERC20FlashMintMock is ERC20FlashMint {
     constructor (

contracts/mocks/ERC20VotesMock.sol

@@ -3,7 +3,7 @@
 pragma solidity ^0.8.0;
 
 
-import "../token/ERC20/extensions/draft-ERC20Votes.sol";
+import "../token/ERC20/extensions/ERC20Votes.sol";
 
 contract ERC20VotesMock is ERC20Votes {
     constructor (

contracts/token/ERC20/extensions/draft-ERC20Votes.sol → contracts/token/ERC20/extensions/ERC20Votes.sol

@@ -3,7 +3,7 @@
 pragma solidity ^0.8.0;
 
 import "./draft-ERC20Permit.sol";
-import "./draft-IERC20Votes.sol";
+import "./IERC20Votes.sol";
 import "../../../utils/math/Math.sol";
 import "../../../utils/math/SafeCast.sol";
 import "../../../utils/cryptography/ECDSA.sol";