key in x-amz-meta headers in lowercase version
key in x-amz-meta headers in lowercase version

passion4code/ngx_aws_auth,irasnyd/ngx_aws_auth,trunkclub/ngx_aws_auth,DreamLab/ngx_aws_auth,irasnyd/ngx_aws_auth,anomalizer/ngx_aws_auth,passion4code/ngx_aws_auth,anomalizer/ngx_aws_auth,trunkclub/ngx_aws_auth,DreamLab/ngx_aws_auth