Use aws-sdk v3 service specific gem

[cosmo0920]

aws-sdk-v3 and service specific gems are released.

For EC2: https://rubygems.org/gems/aws-sdk-ec2

Then, we can migrate to use aws-sdk v3 ec2 specific gem.

ref: https://aws.amazon.com/jp/blogs/developer/upgrading-from-version-2-to-version-3-of-the-aws-sdk-for-ruby-2/

[cosmo0920]

@takus Could you release new version? Depending aws-sdk gem should work but it is very huge gem dependencies. We should depend on service specific AWS SDK gem.

[takus]

@cosmo0920 Just released New version. Always thanks for your contribution 🥇 https://rubygems.org/gems/fluent-plugin-ec2-metadata/versions/0.1.1

[cosmo0920]

Thank you! :smile: