RunDeps attribute
By default, the dependencies of a task are run sequentially, in the order they are listed.
However we may prefer for all the dependencies of a task to be run in paralled.
The solution would be to set the RunDeps attribute to async (defaults to sync).
### build-all
Requires: build-js, build-css
RunDeps: async
This will result in both build-js and build-css being run in parallel.
The default is sync, which can be omitted or specified.
### build-all
Requires: build-js, build-css
RunDeps: sync
is the same as
### build-all
Requires: build-js, build-css