build(deps): Bump google.golang.org/grpc from 1.29.1 to 1.30.0

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.29.1 to 1.30.0.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](https://github.com/grpc/grpc-go/compare/v1.29.1...v1.30.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

go.mod

@@ -28,5 +28,5 @@ require (
 	github.com/tendermint/tm-db v0.5.1
 	golang.org/x/crypto v0.0.0-20200406173513-056763e48d71
 	golang.org/x/net v0.0.0-20200324143707-d3edc9973b7e
-	google.golang.org/grpc v1.29.1
+	google.golang.org/grpc v1.30.0
 )

go.sum

@@ -647,6 +647,8 @@ google.golang.org/grpc v1.28.0 h1:bO/TA4OxCOummhSf10siHuG7vJOiwh7SpRpFZDkOgl4=
 google.golang.org/grpc v1.28.0/go.mod h1:rpkK4SK4GF4Ach/+MFLZUBavHOvF2JJB5uozKKal+60=
 google.golang.org/grpc v1.29.1 h1:EC2SB8S04d2r73uptxphDSUG+kTKVgjRPF+N3xpxRB4=
 google.golang.org/grpc v1.29.1/go.mod h1:itym6AZVZYACWQqET3MqgPpjcuV5QH3BxFS3IjizoKk=
+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/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=