Add support for v0.11 GRPC services

This also refactors the client GRPC wrapper to dynamically load the
request objects.
All GRPC generated client files now live under lib/grpc_services

lib/grpc_services/invoicesrpc/invoices_pb.rb

@@ -0,0 +1,48 @@
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: invoicesrpc/invoices.proto
+
+require 'google/protobuf'
+
+require 'rpc_pb'
+Google::Protobuf::DescriptorPool.generated_pool.build do
+  add_file("invoicesrpc/invoices.proto", :syntax => :proto3) do
+    add_message "invoicesrpc.CancelInvoiceMsg" do
+      optional :payment_hash, :bytes, 1
+    end
+    add_message "invoicesrpc.CancelInvoiceResp" do
+    end
+    add_message "invoicesrpc.AddHoldInvoiceRequest" do
+      optional :memo, :string, 1
+      optional :hash, :bytes, 2
+      optional :value, :int64, 3
+      optional :value_msat, :int64, 10
+      optional :description_hash, :bytes, 4
+      optional :expiry, :int64, 5
+      optional :fallback_addr, :string, 6
+      optional :cltv_expiry, :uint64, 7
+      repeated :route_hints, :message, 8, "lnrpc.RouteHint"
+      optional :private, :bool, 9
+    end
+    add_message "invoicesrpc.AddHoldInvoiceResp" do
+      optional :payment_request, :string, 1
+    end
+    add_message "invoicesrpc.SettleInvoiceMsg" do
+      optional :preimage, :bytes, 1
+    end
+    add_message "invoicesrpc.SettleInvoiceResp" do
+    end
+    add_message "invoicesrpc.SubscribeSingleInvoiceRequest" do
+      optional :r_hash, :bytes, 2
+    end
+  end
+end
+
+module Invoicesrpc
+  CancelInvoiceMsg = ::Google::Protobuf::DescriptorPool.generated_pool.lookup("invoicesrpc.CancelInvoiceMsg").msgclass
+  CancelInvoiceResp = ::Google::Protobuf::DescriptorPool.generated_pool.lookup("invoicesrpc.CancelInvoiceResp").msgclass
+  AddHoldInvoiceRequest = ::Google::Protobuf::DescriptorPool.generated_pool.lookup("invoicesrpc.AddHoldInvoiceRequest").msgclass
+  AddHoldInvoiceResp = ::Google::Protobuf::DescriptorPool.generated_pool.lookup("invoicesrpc.AddHoldInvoiceResp").msgclass
+  SettleInvoiceMsg = ::Google::Protobuf::DescriptorPool.generated_pool.lookup("invoicesrpc.SettleInvoiceMsg").msgclass
+  SettleInvoiceResp = ::Google::Protobuf::DescriptorPool.generated_pool.lookup("invoicesrpc.SettleInvoiceResp").msgclass
+  SubscribeSingleInvoiceRequest = ::Google::Protobuf::DescriptorPool.generated_pool.lookup("invoicesrpc.SubscribeSingleInvoiceRequest").msgclass
+end

lib/grpc_services/invoicesrpc/invoices_services_pb.rb

@@ -0,0 +1,41 @@
+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# Source: invoicesrpc/invoices.proto for package 'invoicesrpc'
+
+require 'grpc'
+require 'invoicesrpc/invoices_pb'
+
+module Invoicesrpc
+  module Invoices
+    # Invoices is a service that can be used to create, accept, settle and cancel
+    # invoices.
+    class Service
+
+      include GRPC::GenericService
+
+      self.marshal_class_method = :encode
+      self.unmarshal_class_method = :decode
+      self.service_name = 'invoicesrpc.Invoices'
+
+      #
+      # SubscribeSingleInvoice returns a uni-directional stream (server -> client)
+      # to notify the client of state transitions of the specified invoice.
+      # Initially the current invoice state is always sent out.
+      rpc :SubscribeSingleInvoice, SubscribeSingleInvoiceRequest, stream(Lnrpc::Invoice)
+      #
+      # CancelInvoice cancels a currently open invoice. If the invoice is already
+      # canceled, this call will succeed. If the invoice is already settled, it will
+      # fail.
+      rpc :CancelInvoice, CancelInvoiceMsg, CancelInvoiceResp
+      #
+      # AddHoldInvoice creates a hold invoice. It ties the invoice to the hash
+      # supplied in the request.
+      rpc :AddHoldInvoice, AddHoldInvoiceRequest, AddHoldInvoiceResp
+      #
+      # SettleInvoice settles an accepted invoice. If the invoice is already
+      # settled, this call will succeed.
+      rpc :SettleInvoice, SettleInvoiceMsg, SettleInvoiceResp
+    end
+
+    Stub = Service.rpc_stub_class
+  end
+end