Fix double quotes ruby

Author: kelvins

src/ruby/busca_sequencial_recursiva.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require 'test/unit/assertions'
+require "test/unit/assertions"
 include Test::Unit::Assertions
 
 # Retorna o índice do elemento. Se não existir, retorna -1.

src/ruby/palindromo.rb

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require 'test/unit/assertions'
+require "test/unit/assertions"
 include Test::Unit::Assertions
 
 # the easiest implementation would be using .reverse method