Add changelog for 1.5.0.

CHANGELOG.md

@@ -1,3 +1,13 @@
+# 1.5.0
+ * Add pluggable name resolution. Users can now override the IP addresses for
+   hostnames of their choice.
+ * bugfix: Don't re-pool streams on drop. This would occur if the user called
+   `response.into_reader()` and dropped the resulting `Read` before reading all
+   the way to EOF. The result would be a BadStatus error on the next request to
+   the same hostname. This only affected users using an explicit Agent.
+ * Automatically set Transfer-Encoding when using `send`.
+ * `into_reader()` now returns `impl Read + Send` instead of `impl Read`.
+
 # 1.4.1
 
  * Use buffer to avoid byte-by-byte parsing result in multiple syscalls.