Grunt improvments

[taylortom]

Couple of improvements needed:

Tracking IDs
We currently have tracking-insert running during the dev and build tasks. It's been requested to remove this from dev, and to also include a check to see if spoor's installed.

Hard-coded course
if the _id in course.json is anything other than course, the build processes fail. This needs to be more flexible.

[taylortom]

See also: #369, #208 (particularly: #208 (comment))

[tomgreenfield]

New package 'columnify' awkwardly double line-breaks its output on Windows. As discussed, may be worth seeing if this can be cleaned up?