Update third_party/protobuf to protobuf-v3.0.0-beta-3

third_party/protobuf/ruby/lib/google/protobuf/repeated_field.rb

Index: third_party/protobuf/ruby/lib/google/protobuf/repeated_field.rb
diff --git a/third_party/protobuf/ruby/lib/google/protobuf/repeated_field.rb b/third_party/protobuf/ruby/lib/google/protobuf/repeated_field.rb
index 16c843c07fa5ad6d3c128d2754a5c043dd0c637c..0ad2060d433293defe4d281b813714c5021a1286 100644
--- a/third_party/protobuf/ruby/lib/google/protobuf/repeated_field.rb
+++ b/third_party/protobuf/ruby/lib/google/protobuf/repeated_field.rb
@@ -69,8 +69,8 @@ module Google
       #        relationship explicit instead of implicit
       def_delegators :to_ary,
         :&, :*, :-, :'<=>',
-        :assoc, :bsearch, :combination, :compact, :count, :cycle,
-        :drop, :drop_while, :eql?, :fetch, :find_index, :flatten,
+        :assoc, :bsearch, :bsearch_index, :combination, :compact, :count,
+        :cycle, :dig, :drop, :drop_while, :eql?, :fetch, :find_index, :flatten,
         :include?, :index, :inspect, :join,
         :pack, :permutation, :product, :pretty_print, :pretty_print_cycle,
         :rassoc, :repeated_combination, :repeated_permutation, :reverse,