Create a table including TTL setting with :table_name keyword argument

[ta1kt0me]

Thank you for your maintenance.
This PR resolves an error that occurs when it calls .create_table with table_name keyword for a Model with TTL set.

A simple reproduced code is below,

require 'dynamoid'

Aws.config.update(
  region: 'us-west-2',
  credentials: Aws::Credentials.new('sample', 'sample')
)

Dynamoid.configure do |config|
  config.namespace = 'dynamoid_app_development'
  config.endpoint = 'http://127.0.0.1:8000'
  config.region = 'us-west-2'
end

Dynamoid.adapter.list_tables.each do |table|
  Dynamoid.adapter.delete_table(table)
end

Dynamoid.adapter.tables.clear

class User
  include Dynamoid::Document

  table expires: { field: :ttl, after: 60 }

  field :ttl, :integer
end

User.create_table(table_name: 'dynamoid_app_test_users')
# => Cannot do operations on a non-existent table (Aws::DynamoDB::Errors::ResourceNotFoundException)

# or

User.create_table
User.create_table(table_name: 'dynamoid_app_test_users')
# => TimeToLive is already enabled (Aws::DynamoDB::Errors::ValidationException)

This is because when setting TTL with .create_table, the table name based on Dynamoid.config.namespace is used instead of the keyword argument :table_name. In this case, changing to use the value of :table_name would solve this problem.

My practical use case is to create tables during development using the db:create hook in Ruby on Rails. I need to create a table for development and a table for testing during development, and call .create_table for each environment. The :table_name keyword argument is required to create the table for testing.

[andrykonchin]

Thank you for the fix! Looks good.