[zendframework/zf2#2659] return a boolean
[zendframework/zf2#2659] return a boolean

- Made the intent cleaner in the canCreateServiceWithName implementation

MadCat34/zend-servicemanager,matwright/zend-servicemanager,prolic/zend-servicemanager,weierophinney/zend-servicemanager,akrabat/zend-servicemanager