Add nim to Docker test image (#37)
Add nim to Docker test image (#37)

CircleCI failing due to `nim` (and `nimble`) not installed thus unable to build properly.
thought-machine/pleasings,thought-machine/pleasings,thought-machine/pleasings,thought-machine/pleasings,thought-machine/pleasings,thought-machine/pleasings,thought-machine/pleasings,thought-machine/pleasings,thought-machine/pleasings,thought-machine/pleasings