add changes to minimum solidity compiler version in the changelog

(cherry picked from commit bddbbe99a73353a959a001ab455490a85003de94)

CHANGELOG.md

@@ -20,8 +20,9 @@
    * `PullPayment.withdrawPayments(address payable payee)`
    * `Escrow.withdraw(address payable payee)`
 
-### Breaking changes in drafts:
- * `SignatureBouncer` has been removed from the library, both to avoid confusions with the GSN Bouncers and `GSNBouncerSignature` and because the API was not very clear. ([#1879](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/1879))
+### Breaking changes:
+ * `Address` now requires a minimum Solidity compiler version of 0.5.5. ([#1802](https://github.com/OpenZeppelin/openzeppelin-solidity/pull/1802))
+ * `SignatureBouncer` has been removed from drafts, both to avoid confusions with the GSN and `GSNRecipientSignature` (previously called `GSNBouncerSignature`) and because the API was not very clear. ([#1879](https://github.com/OpenZeppelin/openzeppelin-contracts/pull/1879))
 
 ## 2.3.0 (2019-05-27)