function validate( opts, options ) {
	if ( !isObject( options ) ) {
		return new TypeError( format( 'invalid argument. Options argument must be an object. Value: `%s`.', options ) );
	}
	if ( hasOwnProp( options, 'devDependencies' ) ) {
		opts.devDependencies = options.devDependencies;
		if ( !isStringArray( opts.devDependencies ) ) {
			return new TypeError( format( 'invalid option. `%s` option must be an array of strings. Option: `%s`.', 'devDependencies', opts.devDependencies ) );
		}
	}
	return null;
}
Validates function options.

@private
@param {Object} opts - destination object
@param {Options} options - function options
@param {Array} [options.devDependencies] - development dependencies to be added
@returns {(Error|null)} null or an error object

@example
var opts = {};
var options = {
    'devDependencies': [ 'tape' ]
};
var err = validate( opts, options );
if ( err ) {
    throw err;
}