Support Vector Machine

Extends [classifier](https://github.com/arrayfire/arrayfire_ml/issues/16). Needs more thought.

Start by reading the classifier issue linked as #16 and determine how a support vector machine should extend it. The issue says it needs more thought but names no files, tests, entry points, or acceptance criteria, so the design and definition of done must be clarified before implementation.

索引モデルが issue の本文から書いたものです。