Allow configuration options includeOptional, ignoreDefaults, and strictExample.

[WesTyler]

Refactors Felicity skeleton to move input inside of options object along with new config options:

const options = {
    input: {},
    config: {
        includeOptional: true,
        ignoreDefaults: true
    }
};
const schema = Joi.object();

const felicityInstance = new Felicity.skeleton(schema, options);

Adds options to Felicity example:

const options = {
    config: {
        strictExample: true,
        ignoreDefaults: true
    }
};
const schema = Joi.object();

const example = Felicity.example(schema, options);

[WesTyler]

Closes #19