[MAINTENANCE] Make configuration files conformant to code conventions

[oscarcs]

As discovered in #241, some of the configuration files (including, ironically, the tslint file itself) are not conformant with the code conventions (mostly wrong indentation).

This is not a particularly important fix, but someone with a bit of extra time might want to tackle it.

Acceptance criteria
All config files are conformant with the project code conventions. This may include reconfiguring the linter to ensure that all of the files are checked by it.

[rmberriman]

Such a shame tslint isn't as well :/ Approved

[nathan-cairns]

haha Approved.

[twchen97]

Approved!