Update changelog(s), esp. for rand_core v0.6

CHANGELOG.md

@@ -36,6 +36,8 @@ You may also find the [Upgrade Guide](https://rust-random.github.io/book/update.
 - The `nightly` feature no longer implies the `simd_support` feature (#1048)
 - Fix `simd_support` feature to work on current nightlies (#1056)
 - Improve accuracy and performance of `IteratorRandom::choose` (#1059)
+- `ReadRng::next_u32` and `next_u64` now use little-Endian conversion instead
+  of native-Endian, affecting results on Big-Endian platforms (#1026)
 
 ## [0.7.3] - 2020-01-10
 ### Fixes

rand_core/CHANGELOG.md

@@ -4,6 +4,17 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+- Bump MSRV to 1.36, various code improvements (#1011)
+- Update to getrandom v0.2 (#1041)
+- Fix: `next_u32_via_fill` and `next_u64_via_fill` now use LE as documented (#?)
+- Reduce usage of `unsafe` (#962, #963, #1011)
+- Annotate feature-gates in documentation (#1019)
+- Various documentation tweaks
+- Fix some clippy warnings (#1036)
+- Apply rustfmt (#926)
+
 ## [0.5.1] - 2019-08-28
 - `OsRng` added to `rand_core` (#863)
 - `Error::INTERNAL_START` and `Error::CUSTOM_START` constants (#864)