Update wasmtime to version 0.20

The version we were using in CI is now getting quite old, and we
want to make sure that the code we produce is compatible with
current versions of Wasmtime.
bb14bd35bdFrank Denis committed on 11/4/2020, 7:28:54 PM· committed by Jakub Konkaparent342ba96
1 file changedLine totals unavailable