Where do I find the 'Declaration of conformity' in Horizon2020?

They are now called ”Researcher Declarations” and are even more important in Horizon2020, as reporting is automated (the data from the declarations will be fed directly to the reporting system). The declarations will be electronic. You can find them here e.g.:
http://ec.europa.eu/research/participants/data/ref/h2020/grants_manual/amga/h2020-amga_en.pdf page 398