add more matcher 3

[levaleureux]

Nil:

be_nil: Verifies that a value is nil. Exceptions:

raise_error: Verifies that an exception is raised. raise_error(ErrorClass): Verifies that an exception of the specified class is raised. Respond_to:

respond_to(:method_name): Verifies that an object responds to the specified method. Satisfy:

satisfy { |value| ... }: Verifies that the value satisfies a custom condition specified in the block. This is just a partial list of the matchers available in RSpec. You can find the complete list and more details in the official RSpec documentation: https://rspec.info/documentation/3.10/rspec-expectations/

[levaleureux]

Improve doc with https://www.tutorialspoint.com/rspec/rspec_matchers.htm not there is no match? matcher because there no regex in dragonruby.

[levaleureux]

be nil is done