set deployment target to 7.0
update Parse SDK to v1.6.0
remove a workaround

Because HBFav2.app can be built without this workaround when use new Parse SDK.
This workaround was added at https://github.com/naoya/HBFav2/commit/1ab27044ee82d1b565bd5a668eb3b55190f3807f
Merge pull request #121 from Watson1978/64bit

Support 64bit app