Added support for preserving transparency when converting from color to greyscale
Added support for preserving transparency when converting from color to greyscale

tawanda/django-imagekit,tawanda/django-imagekit,pcompassion/django-imagekit,FundedByMe/django-imagekit,pcompassion/django-imagekit,pcompassion/django-imagekit,FundedByMe/django-imagekit