update changelog

CHANGELOG.md

@@ -1,5 +1,28 @@
 # Changelog
 
+## v0.31.5
+
+*April 16th, 2019*
+
+This release fixes a regression from v0.31.4 where, in existing chains that
+were upgraded, `/validators` could return an empty validator set. This is true
+for almost all heights given the validator set remains the same.
+
+Special thanks to external contributors on this release:
+@brapse, @guagualvcha, @dongsam, @phucc
+
+### IMPROVEMENTS:
+
+- [libs/common] CMap: slight optimization in Keys() and Values() (@phucc)
+- [gitignore] gitignore: add .vendor-new (@dongsam)
+
+### BUG FIXES:
+
+- [state] [\#3537](https://github.com/tendermint/tendermint/pull/3537#issuecomment-482711833)
+  LoadValidators: do not return an empty validator set
+- [blockchain] [\#3457](https://github.com/tendermint/tendermint/issues/3457)
+  Fix "peer did not send us anything" in `fast_sync` mode when under high pressure
+
 ## v0.31.4
 
 *April 12th, 2019*
@@ -16,6 +39,7 @@ Special thanks to external contributors on this release:
 @brapse, @guagualvcha, @mydring
 
 ### IMPROVEMENTS:
+
 - [p2p] [\#3463](https://github.com/tendermint/tendermint/pull/3463) Do not log "Can't add peer's address to addrbook" error for a private peer
 - [p2p] [\#3547](https://github.com/tendermint/tendermint/pull/3547) Fix a couple of annoying typos (@mdyring)
 

CHANGELOG_PENDING.md

@@ -1,4 +1,4 @@
-## v0.31.5
+## v0.31.6
 
 **
 
@@ -19,4 +19,3 @@
 ### IMPROVEMENTS:
 
 ### BUG FIXES:
-- [state] [\#3537](https://github.com/tendermint/tendermint/pull/3537#issuecomment-482711833) LoadValidators: do not return an empty validator set