Change `sf::Event::EventType::KeyPressed` to `sf::Event::KeyPressed`

From build output:

Compiling InterfaceManager.cpp
InterfaceManager.cpp: In member function ‘void SFMLInterfacePkg::InterfaceManager::handleEvent()’:
InterfaceManager.cpp:348:37: error: ‘sf::Event::EventType’ is not a class or namespace
         if(event.type == sf::Event::EventType::KeyPressed)
                                     ^
Test.mak:147: recipe for target 'InterfaceManager.o' failed
make: *** [InterfaceManager.o] Error 1

Also see: http://stackoverflow.com/questions/13895555/eventtype-is-not-a-class-or-namespace