Change default for logging in CloudTrail to true
Change default for logging in CloudTrail to true

The default for `enable_logging`, which defines whether CloudTrail
actually logs events was originally written as defaulting to `false`,
since that's how AWS creates trails.

`true` is likely a better default for Terraform users.

Changed the default and updated the docs.
Changed the acceptance tests to verify new default behavior.

ashinohara/terraform-provider-aws,ClementCunin/terraform-provider-aws,Ninir/terraform-provider-aws,ashinohara/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,ClementCunin/terraform-provider-aws,ashinohara/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,kjmkznr/terraform-provider-aws,kjmkznr/terraform-provider-aws,ClementCunin/terraform-provider-aws,terraform-providers/terraform-provider-aws,terraform-providers/terraform-provider-aws,ClementCunin/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,terraform-providers/terraform-provider-aws,Ninir/terraform-provider-aws,charles-at-geospock/terraform-provider-aws,kjmkznr/terraform-provider-aws,ashinohara/terraform-provider-aws,nbaztec/terraform-provider-aws,nbaztec/terraform-provider-aws,nbaztec/terraform-provider-aws,Ninir/terraform-provider-aws,nbaztec/terraform-provider-aws,terraform-providers/terraform-provider-aws,Ninir/terraform-provider-aws,kjmkznr/terraform-provider-aws