Rename Strings.fromUint256 to Strings.toString (#2188)

* rename Strings.fromUint256 to Strings.toString

* add changelog entry

* fix conflict with js toString method

CHANGELOG.md

@@ -35,6 +35,7 @@
  * `ERC721`: added a constructor for `name` and `symbol`. ([#2160](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2160))
  * `ERC20Detailed`: this contract was removed and its functionality merged into `ERC20`. ([#2161](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2161))
  * `ERC20`: added a constructor for `name` and `symbol`. `decimals` now defaults to 18. ([#2161](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2161))
+ * `Strings`: renamed `fromUint256` to `toString` ([#2188](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2188))
 
 ## 2.5.0 (2020-02-04)
 

contracts/mocks/StringsMock.sol

@@ -4,6 +4,6 @@ import "../utils/Strings.sol";
 
 contract StringsMock {
     function fromUint256(uint256 value) public pure returns (string memory) {
-        return Strings.fromUint256(value);
+        return Strings.toString(value);
     }
 }

contracts/token/ERC721/ERC721.sol

@@ -153,7 +153,7 @@ contract ERC721 is Context, ERC165, IERC721, IERC721Metadata, IERC721Enumerable
             return string(abi.encodePacked(_baseURI, _tokenURI));
         }
         // If there is a baseURI but no tokenURI, concatenate the tokenID to the baseURI.
-        return string(abi.encodePacked(_baseURI, Strings.fromUint256(tokenId)));
+        return string(abi.encodePacked(_baseURI, Strings.toString(tokenId)));
     }
 
     /**

contracts/utils/Strings.sol

 pragma solidity ^0.6.0;
 
 /**
- * @title Strings
  * @dev String operations.
  */
 library Strings {
     /**
      * @dev Converts a `uint256` to its ASCII `string` representation.
      */
-    function fromUint256(uint256 value) internal pure returns (string memory) {
+    function toString(uint256 value) internal pure returns (string memory) {
         // Inspired by OraclizeAPI's implementation - MIT licence
         // https://github.com/oraclize/ethereum-api/blob/b42146b063c7d6ee1358846c198246239e9360e8/oraclizeAPI_0.4.25.sol