Bump buildkit to master and fix versions incompatible with go mod 1.13

Bump github.com/gogo/googleapis to v1.3.2
Bump github.com/docker/cli to master

Signed-off-by: Silvin Lubecki <silvin.lubecki@docker.com>

vendor/github.com/moby/buildkit/frontend/gateway/pb/caps.go

@@ -19,6 +19,19 @@ const (
 	CapReadDir                 apicaps.CapID = "readdir"
 	CapStatFile                apicaps.CapID = "statfile"
 	CapImportCaches            apicaps.CapID = "importcaches"
+
+	// CapProtoRefArray is a capability to return arrays of refs instead of single
+	// refs. This capability is only for the wire format change and shouldn't be
+	// used in frontends for feature detection.
+	CapProtoRefArray apicaps.CapID = "proto.refarray"
+
+	// CapReferenceOutput is a capability to use a reference of a solved result as
+	// an llb.Output.
+	CapReferenceOutput apicaps.CapID = "reference.output"
+
+	// CapFrontendInputs is a capability to request frontend inputs from the
+	// LLBBridge GRPC server.
+	CapFrontendInputs apicaps.CapID = "frontend.inputs"
 )
 
 func init() {
@@ -92,4 +105,25 @@ func init() {
 		Enabled: true,
 		Status:  apicaps.CapStatusExperimental,
 	})
+
+	Caps.Init(apicaps.Cap{
+		ID:      CapProtoRefArray,
+		Name:    "wire format ref arrays",
+		Enabled: true,
+		Status:  apicaps.CapStatusExperimental,
+	})
+
+	Caps.Init(apicaps.Cap{
+		ID:      CapReferenceOutput,
+		Name:    "reference output",
+		Enabled: true,
+		Status:  apicaps.CapStatusExperimental,
+	})
+
+	Caps.Init(apicaps.Cap{
+		ID:      CapFrontendInputs,
+		Name:    "frontend inputs",
+		Enabled: true,
+		Status:  apicaps.CapStatusExperimental,
+	})
 }

vendor/github.com/moby/buildkit/frontend/gateway/pb/gateway.proto

@@ -26,20 +26,35 @@ service LLBBridge {
 	rpc StatFile(StatFileRequest) returns (StatFileResponse);
 	rpc Ping(PingRequest) returns (PongResponse);
 	rpc Return(ReturnRequest) returns (ReturnResponse);
+	// apicaps:CapFrontendInputs
+	rpc Inputs(InputsRequest) returns (InputsResponse);
 }
 
 message Result {
 	oneof result {
-		string ref = 1;
-		RefMap refs = 2;
+    		// Deprecated non-array refs.
+		string refDeprecated = 1;
+		RefMapDeprecated refsDeprecated = 2;
+
+		Ref ref = 3;
+		RefMap refs = 4;
 	}
 	map<string, bytes> metadata = 10;
 }
 
-message RefMap {
+message RefMapDeprecated {
 	map<string, string> refs = 1;
 }
 
+message Ref {
+	string id = 1;
+	pb.Definition def = 2;
+}
+
+message RefMap {
+	map<string, Ref> refs = 1;
+}
+
 message ReturnRequest {
 	Result result = 1;
 	google.rpc.Status error = 2;
@@ -48,6 +63,13 @@ message ReturnRequest {
 message ReturnResponse {
 }
 
+message InputsRequest {
+}
+
+message InputsResponse {
+    map<string, pb.Definition> Definitions = 1;
+}
+
 message ResolveImageConfigRequest {
 	string Ref = 1;
 	pb.Platform Platform = 2;
@@ -70,6 +92,7 @@ message SolveRequest {
         // for each of the ImportCacheRefs entry to CacheImports for compatibility. (planned to be removed)
 	repeated string ImportCacheRefsDeprecated = 4;
 	bool allowResultReturn = 5;
+	bool allowResultArrayRef = 6;
 	
 	// apicaps.CapSolveInlineReturn deprecated
 	bool Final = 10;
@@ -77,6 +100,9 @@ message SolveRequest {
 	// CacheImports was added in BuildKit v0.4.0.
 	// apicaps:CapImportCaches
 	repeated CacheOptionsEntry CacheImports = 12;
+
+	// apicaps:CapFrontendInputs
+	map<string, pb.Definition> FrontendInputs = 13;
 }
 
 // CacheOptionsEntry corresponds to the control.CacheOptionsEntry