Set up AWS SDK log level to debug
Set up AWS SDK log level to debug

Because AWS SDK logger mechanism does not consider log_level but
it always uses specified log_level.

See: https://github.com/aws/aws-sdk-ruby/blob/97b28ccf18558fc908fd56f52741cf3329de9869/gems/aws-sdk-core/lib/aws-sdk-core/plugins/logging.rb#L50-L52

Fixes #175

Signed-off-by: Hiroshi Hatake <a476a6e5b5893650242fbf0b2961500a9bd9032e@clear-code.com>

ryotarai/fluent-plugin-cloudwatch-logs