Busted now only provides the magic modules `assert`, `spy` etc for
the busted context. The helper module `spec/wibox/test_utils.lua`
therefore needs to explicitly require them.
Ref: https://github.com/awesomeWM/awesome/pull/139
This uses busted (http://olivinelabs.com/busted/) to implement unit testing.
This is wired up to "make check" and/or "make test".
This commit also adds tests for the more complicated parts of the gears and
wibox.layout libraries.
Signed-off-by: Uli Schlachter <psychon@znc.in>