Improve Numericality validator.

[esbanarango]

This validator should accept the same options as the Active Record Numericality validator.

• only_integer
• greater_than - Specifies the value must be greater than the supplied value. The default error message for this option is "must be greater than %{count}".
• greater_than_or_equal_to - Specifies the value must be greater than or equal to the supplied value. The default error message for this option is "must be greater than or equal to %{count}".
• equal_to - Specifies the value must be equal to the supplied value. The default error message for this option is "must be equal to %{count}".
• less_than - Specifies the value must be less than the supplied value. The default error message for this option is "must be less than %{count}".
• less_than_or_equal_to - Specifies the value must be less than or equal the supplied value. The default error message for this option is "must be less than or equal to %{count}".
• odd - Specifies the value must be an odd number if set to true. The default error message for this option is "must be odd".
• even - Specifies the value must be an even number if set to true. The default error message for this option is "must be even".