reformat: remove trailing whitespace.

* lib/zile/FileString.lua: Remove trailing whitespace.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
slingshot: sync with upstream.

* slingshot: Sync with upstream for github raw url changes.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>
travis: we rely on bugfixes from unreleased specl master.

* .travis.yml (script): Install specl git master directly from
github.

Signed-off-by: Gary V. Vaughan <gary@gnu.org>