Bump google.golang.org/grpc from 1.30.0 to 1.31.0

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.30.0 to 1.31.0.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](https://github.com/grpc/grpc-go/compare/v1.30.0...v1.31.0)

Signed-off-by: dependabot-preview[bot] <[email protected]>

go.mod

@@ -1,6 +1,7 @@
 module github.com/docker/api
 
 go 1.14
+
 // the distribution version from ecs plugin is quite old and it breaks containerd
 // we need to create a new release tag for docker/distribution
 replace github.com/docker/distribution => github.com/docker/distribution v0.0.0-20200708230824-53e18a9d9bfe
@@ -52,7 +53,7 @@ require (
 	golang.org/x/oauth2 v0.0.0-20190604053449-0f29369cfe45
 	golang.org/x/sync v0.0.0-20190423024810-112230192c58
 	golang.org/x/sys v0.0.0-20200519105757-fe76b779f299 // indirect
-	google.golang.org/grpc v1.30.0
+	google.golang.org/grpc v1.31.0
 	google.golang.org/protobuf v1.25.0
 	gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 // indirect
 	gopkg.in/ini.v1 v1.57.0

go.sum

@@ -646,6 +646,8 @@ google.golang.org/grpc v1.25.1/go.mod h1:c3i+UQWmh7LiEpx4sFZnkU36qjEYZ0imhYfXVyQ
 google.golang.org/grpc v1.27.0/go.mod h1:qbnxyOmOxrQa7FizSgH+ReBfzJrCY1pSN7KXBS8abTk=
 google.golang.org/grpc v1.30.0 h1:M5a8xTlYTxwMn5ZFkwhRabsygDY5G8TYLyQDBxJNAxE=
 google.golang.org/grpc v1.30.0/go.mod h1:N36X2cJ7JwdamYAgDz+s+rVMFjt3numwzf/HckM8pak=
+google.golang.org/grpc v1.31.0 h1:T7P4R73V3SSDPhH7WW7ATbfViLtmamH0DKrP3f9AuDI=
+google.golang.org/grpc v1.31.0/go.mod h1:N36X2cJ7JwdamYAgDz+s+rVMFjt3numwzf/HckM8pak=
 google.golang.org/protobuf v0.0.0-20200109180630-ec00e32a8dfd/go.mod h1:DFci5gLYBciE7Vtevhsrf46CRTquxDuWsQurQQe4oz8=
 google.golang.org/protobuf v0.0.0-20200221191635-4d8936d0db64/go.mod h1:kwYJMbMJ01Woi6D6+Kah6886xMZcty6N08ah7+eCXa0=
 google.golang.org/protobuf v0.0.0-20200228230310-ab0ca4ff8a60/go.mod h1:cfTl7dwQJ+fmap5saPgwCLgHXTUD7jkjRqWcaiX5VyM=