gitmodules: remote URL changed to github.com/twbs

Signed-off-by: Michael Turquette <mturquette@deferred.io>
twbs: update to v3.0.3

Signed-off-by: Michael Turquette <mturquette@deferred.io>
NOTES.md: WIP notes. delete before publishing

Signed-off-by: Michael Turquette <mturquette@deferred.io>