add sml-mode expansion for fun and val definitions

This adds just one expansion by function and value definitions, by
relying on sml-mode's own function.

The function sml-mode-expansions.el also provides a stub for adding
further sml-mode expansions.
Merge pull request #96 from algal/feature-sml-expansions

add sml-mode expansion for fun and val definitions
Travis: Disable fgallina tests below Emacs 24.3
Travis: Fix .travis.yml syntax
Pull basic expansions into own file.
Add expansions for email and url
Add Alexis Gallagher (@algal) to list of contributors
Release 0.9.0