azure-core history 1.0.0b2 (#6562)

* azure-core history

* Update HISTORY.md

sdk/core/azure-core/HISTORY.md

@@ -3,6 +3,27 @@
 
 -------------------
 
+2019-08-XX Version 1.0.0b2
+
+## Breaking changes
+
+- Transport classes don't take `config` parameter anymore (use kwargs instead)  #6372
+- `azure.core.paging` has been completely refactored  #6420
+- HttpResponse.content_type attribute is now a string (was a list)  #6490
+- For `StreamDownloadGenerator` subclasses, `response` is now an `HttpResponse`, and not a transport response like `aiohttp.ClientResponse` or `requests.Response`. The transport response is available in `internal_response` attribute  #6490
+
+## Bug fixes
+
+- aiohttp is not required to import async pipelines classes #6496
+- `AsyncioRequestsTransport.sleep` is now a coroutine as expected #6490
+- `RequestsTransport` is not tight to `ProxyPolicy` implementation details anymore #6372
+- `AiohttpTransport` does not raise on unexpected kwargs  #6355
+
+## Features
+
+- New paging base classes that support `continuation_token` and `by_page()`  #6420
+- Proxy support for `AiohttpTransport`  #6372
+
 2019-06-26 Version 1.0.0b1
 
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