Update to suasync v1.3.3.
Make the write path fully asynchronous.

Lookup or create all UIDs asynchronously, which was the last
step required to make the write path truly, fully asynchronous.
Previously the data point itself was written asynchronously,
but if we had a lot of new metrics or tags to create or lookup,
these were happening serially.

The net side effect of this change is that if multiple tags
need to be created for a single data point, they are now all
created concurrently.
Modify Deferred.group() callbacks to include a type due to the async library
template change in 1.3.3.