Topic/reqs 507

Added zero coupon example ([PLAT-6812] Added ZC swap example, https://github.com/OpenGamma/OG-Platform/commit/d1b03f8eee30d96dd1497cc95d995dfd06292f7e and [PLAT-6812] Removed unnecessary setup https://github.com/OpenGamma/OG-Platform/commit/7b7d2df96cff89ab7a58878294a405b08768c3d1 ).