In-App purchasing demo
 QT += quick qml quickcontrols2
 INCLUDEPATH += purchasing/qmltypes \
     purchasing/inapp
 CONFIG += qmltypes
 QML_IMPORT_PATH = $$PWD/hangmangame.h
 QML_IMPORT_NAME = Hangman
 QML_IMPORT_MAJOR_VERSION = 1
 SOURCES += $$PWD/main.cpp \
     $$PWD/hangmangame.cpp
 HEADERS += $$PWD/hangmangame.h
 RESOURCES += resources.qrc
 target.path = $$[QT_INSTALL_EXAMPLES]/demos/hangman
 INSTALLS += target
 include($$PWD/purchasing/purchasing.pri)