Use upload() instead of create_log() and update t_0 in update_if_dqok
Partially implements the changes in !1242 (closed) at the request of @leo-singer
Does not change the API requests made or the retry behavior. Return value of check_vectors is used to get the gpstime of the event to avoid #647 (closed).
Requires a more convoluted test case, since we need to mock the behavior of get_labels
and check_vectors
both, instead of just mocking the return value of check_vectors