devel/ruby-necromancer: add version 0.5.0 package

Add ruby-necromancer version 0.5.0 package.

Necromancer

> Conversion from one object type to another with a bit of black magic.

Necromancer provides independent type conversion component for [TTY]
(https://github.com/piotrmurach/tty) toolkit.

## Motivation

Conversion between Ruby core types frequently comes up in projects but is solved by half-baked solutions. This library aims to provide an independent and extensible API to support a robust and generic way to convert between core Ruby types.

## Features

* Simple and expressive API
* Ability to specify own converters
* Ability to compose conversions out of simpler ones
* Support conversion of custom defined types
* Ability to specify strict conversion mode

(taca)