gapic-common has a bunch of YARD warnings

[dazuma]

[warn]: @param tag has unknown parameter name: key 
    in file `lib/gapic/config.rb' near line 51
[warn]: @param tag has unknown parameter name: initial 
    in file `lib/gapic/config.rb' near line 51
[warn]: @param tag has unknown parameter name: opts 
    in file `lib/gapic/config.rb' near line 51
[warn]: Invalid tag format for @yield in file `lib/gapic/operation.rb` near line 255
[warn]: Invalid tag format for @yield in file `lib/gapic/operation.rb` near line 275
[warn]: @param tag has duplicate parameter name: retry_policy 
    in file `lib/gapic/call_options.rb' near line 66
[warn]: Invalid tag format for @return in file `lib/gapic/rest/grpc_transcoder.rb` near line 130
[warn]: Invalid tag format for @yield in file `lib/gapic/generic_lro/operation.rb` near line 201
[warn]: Invalid tag format for @yield in file `lib/gapic/generic_lro/operation.rb` near line 221
[warn]: Invalid tag format for @yield in file `lib/gapic/generic_lro/operation.rb` near line 232
[warn]: @param tag has unknown parameter name: request 
    in file `lib/gapic/rest/transport_operation.rb' near line 33
[warn]: In file `lib/gapic/operation.rb':121: Cannot resolve link to Google::Protobuf::DescriptorPool.generated_pool from text:
	{Google::Protobuf::DescriptorPool.generated_pool}...
[warn]: In file `lib/gapic/operation.rb':98: Cannot resolve link to Google::Rpc::Status from text:
	{Google::Rpc::Status}...
[warn]: In file `lib/gapic/call_options.rb':35: Cannot resolve link to RetryPolicy.new from text:
	...{RetryPolicy.new}...