Fix Ruby 2.7 deprecation warnings

Author: ngan

lib/database_cleaner/cleaners.rb

@@ -7,9 +7,9 @@ def initialize hash={}
  end
 
  # FIXME this method conflates creation with lookup... both a command and a query. yuck.
- def [](orm, opts = {})
+ def [](orm, **opts)
  raise ArgumentError if orm.nil?
- fetch([orm, opts]) { add_cleaner(orm, opts) }
+ fetch([orm, opts]) { add_cleaner(orm, **opts) }
  end 
 
  def strategy=(strategy)
@@ -37,8 +37,8 @@ def clean_with(*args)
 
  private
 
- def add_cleaner(orm, opts = {})
- self[[orm, opts]] = Cleaner.new(orm, opts)
+ def add_cleaner(orm, **opts)
+ self[[orm, opts]] = Cleaner.new(orm, **opts)
  end
 
  def remove_duplicates