Update Speakers to use php 7 features
Update Speakers to use php 7 features

Added return types and type declarations where possible in Speakers

localheinz/opencfp,localheinz/opencfp,mdwheele/opencfp,opencfp/opencfp,opencfp/opencfp,opencfp/opencfp,GrUSP/opencfp,mdwheele/opencfp,mdwheele/opencfp,localheinz/opencfp,GrUSP/opencfp,localheinz/opencfp,GrUSP/opencfp,mdwheele/opencfp,GrUSP/opencfp,PHPBenelux/opencfp,PHPBenelux/opencfp,PHPBenelux/opencfp,PHPBenelux/opencfp