[upstream] Slimer doesn't exit with proper exit code

[bensu]

See https://github.com/laurentj/slimerjs/pull/278

[bensu]

This will be solved in Slimer's next release.

[danielcompton]

The test commands in circle.yml will also need to be uncommented when this fix is released.

[bensu]

Slimer's 0.10 is here and solves this issue, but it hasn't made its way to convenient installation methods like brew or npm yet.

[timgilbert]

SlimerJS 0.10.1 is available on homebrew now (and I've verified that slimer.exit(42) works correctly). I haven't tried it on CircleCI personally, but I presume it's installable via this method.