tree 59237e69d8db26d31b5e6336787d8dc3002b5e23
parent 7cea86c4b28c211407310f06840c8b57c2896831
author Paul J. Davis <paul.joseph.davis@gmail.com> 1549583319 -0600
committer Paul J. Davis <paul.joseph.davis@gmail.com> 1549583392 -0600

Add missing void future type

I initially misread the docs and thought some futures just returned
empty values instead of no value whatsoever. This accounts for that
new reality.