Adding missing header where std::iota is declared.
Adding missing header where std::iota is declared.

Change-Id: Ib005bd145a7262130b6775ec3d87ca56c968ec75

mylxiaoyi/TheiaSfM,rajvishah/TheiaSfM,klemmster/TheiaSfM,mylxiaoyi/TheiaSfM,zhanshenman/TheiaSfM,zhanshenman/TheiaSfM,mylxiaoyi/TheiaSfM,rajvishah/TheiaSfM,klemmster/TheiaSfM,zhanshenman/TheiaSfM,zhanshenman/TheiaSfM,mylxiaoyi/TheiaSfM,klemmster/TheiaSfM,mylxiaoyi/TheiaSfM,klemmster/TheiaSfM,zhanshenman/TheiaSfM,rajvishah/TheiaSfM,rajvishah/TheiaSfM,klemmster/TheiaSfM