Added PHP 5.6 to Travis configuration
Added PHP 5.6 to Travis configuration

sunshinephp/opencfp,monoku/opencfp,opencfp/opencfp,opencfp/opencfp,OpenWestConference/opencfp,PHPmvd/phpday-cfp,GrUSP/opencfp,mdwheele/opencfp,zymsys/opencfp,MidwestPHP/opencfp_mwphp15,DragonBe/opencfp-azure,PHPBenelux/opencfp,PHPBenelux/opencfp,madisonphp/opencfp,DallasPHP/opencfp,MidwestPHP/opencfp_mwphp15,monoku/opencfp,madisonphp/opencfp,zhenqing/opencfp,localheinz/opencfp,sunshinephp/opencfp,GrUSP/opencfp,zymsys/opencfp,DragonBe/opencfp-azure,noahd1/opencfp,jugisahunk/200OK_CFP,MidwestPHP/opencfp_mwphp15,Acidburn0zzz/opencfp,localheinz/opencfp,jugisahunk/200OK_CFP,GrUSP/opencfp,OpenWestConference/opencfp,pmeth/opencfp,localheinz/opencfp,DragonBe/opencfp-azure,mdwheele/opencfp,PHPmvd/phpday-cfp,MidwestPHP/opencfp_mwphp15,chrispecoraro/opencfp,DragonBe/opencfp-azure,xavierleune/cfp,madisonphp/opencfp,brynary/opencfp,OpenWestConference/opencfp,zymsys/opencfp,opencfp/opencfp,PHPBenelux/opencfp,Acidburn0zzz/opencfp,GrUSP/opencfp,Acidburn0zzz/opencfp,pmeth/opencfp,jugisahunk/200OK_CFP,chrispecoraro/opencfp,mdwheele/opencfp,zhenqing/opencfp,DallasPHP/opencfp,brynary/opencfp,xavierleune/cfp,xavierleune/cfp,monoku/opencfp,phphants/opencfp,mdwheele/opencfp,localheinz/opencfp,phphants/opencfp,zhenqing/opencfp,sunshinephp/opencfp,noahd1/opencfp,noahd1/opencfp,DragonBe/opencfp-azure,DevOpsDaysChicago/opencfp,OpenWestConference/opencfp,DallasPHP/opencfp,phphants/opencfp,monoku/opencfp,pmeth/opencfp,phphants/opencfp,brynary/opencfp,DevOpsDaysChicago/opencfp,DevOpsDaysChicago/opencfp,PHPBenelux/opencfp