assert [1, 3].includes?(2) fails with unhelpful "Asserting failed" message
assert_includes [1, 3], 2 fails with "Expected [1, 3] to include 2" which makes it easier to debug and more obvious what went wrong
Example:
```ruby
class Person
include ActiveModel::Validations
attr_reader :name, :title
validates_presence_of :name, on: :create
validates_presence_of :title, on: :update
end
person = Person.new
person.valid?([:create, :update]) # => true
person.errors.messages # => {:name=>["can't be blank"], :title=>["can't be blank"]}
```
Example:
```ruby
class Person
include ActiveModel::Validations
attr_reader :name, :title
validates_presence_of :name, on: :create
validates_presence_of :title, on: :update
end
person = Person.new
person.valid?([:create, :update]) # => true
person.errors.messages # => {:name=>["can't be blank"], :title=>["can't be blank"]}
```
