docs(CHANGELOG): update for 0.3.1

CHANGELOG.md

 # go-graphsync changelog
 
+# go-graphsync 0.3.1
+
+Security fix -- switch to google protobufs
+
+### Changelog
+
+- github.com/ipfs/go-graphsync:
+  - Switch to google protobuf generator (#105) ([ipfs/go-graphsync#105](https://github.com/ipfs/go-graphsync/pull/105))
+  - feat(CHANGELOG): update for 0.3.0 ([ipfs/go-graphsync#104](https://github.com/ipfs/go-graphsync/pull/104))
+
+### Contributors
+
+| Contributor | Commits | Lines ± | Files Changed |
+|-------------|---------|---------|---------------|
+| Hannah Howard | 1 | +472/-1553 | 8 |
+
 # go-graphsync 0.3.0
 
 Significant updates allow for:

message/pb/message.pb.go

@@ -7,11 +7,12 @@
 package graphsync_message_pb
 
 import (
+	reflect "reflect"
+	sync "sync"
+
 	_ "github.com/gogo/protobuf/gogoproto"
 	protoreflect "google.golang.org/protobuf/reflect/protoreflect"
 	protoimpl "google.golang.org/protobuf/runtime/protoimpl"
-	reflect "reflect"
-	sync "sync"
 )
 
 const (