Updating protobuf for v1.5 (google#659)

Bringing this in sync with the latest changes and clarifications for v1.5

Adds:
* Report Type
* Days since onset
* revised_keys to list revoked / revised keys

go.mod

@@ -69,7 +69,7 @@ require (
  go.uber.org/zap v1.14.1
  golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d
  golang.org/x/time v0.0.0-20200416051211-89c76fbcd5d1 // indirect
- golang.org/x/tools v0.0.0-20200513154647-78b527d18275
+ golang.org/x/tools v0.0.0-20200623204733-f8e0ea3a3a8f
  google.golang.org/api v0.25.0
  google.golang.org/genproto v0.0.0-20200527145253-8367513e4ece
  google.golang.org/grpc v1.29.1

go.sum

@@ -1472,8 +1472,8 @@ golang.org/x/tools v0.0.0-20200331025713-a30bf2db82d4/go.mod h1:Sl4aGygMT6LrqrWc
 golang.org/x/tools v0.0.0-20200409170454-77362c5149f0/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
 golang.org/x/tools v0.0.0-20200416214402-fc959738d646/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
 golang.org/x/tools v0.0.0-20200501065659-ab2804fb9c9d/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
-golang.org/x/tools v0.0.0-20200513154647-78b527d18275 h1:e7nYe9s94RHunFJ7b+mmPxiQMOKMVSqYASToWb1EcHs=
-golang.org/x/tools v0.0.0-20200513154647-78b527d18275/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
+golang.org/x/tools v0.0.0-20200623204733-f8e0ea3a3a8f h1:YEIftClo4BKh5aFw0WNXGDU/uTfmS9yIUAvX77+O2zg=
+golang.org/x/tools v0.0.0-20200623204733-f8e0ea3a3a8f/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
 golang.org/x/xerrors v0.0.0-20190410155217-1f06c39b4373/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20190513163551-3ee3066db522/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=