Add cubicCentimeters to Volume module

[g-belmonte]

Hey there, @ianmackenzie !

I opened this MR implementing the cubic centimeters as an alias of milliliters, as I understood from https://github.com/ianmackenzie/elm-units/issues/52

Let me know your thoughts :smile:

[ianmackenzie]

Looks good, and thanks for adding tests as well! Only a couple very minor comments:

• I think it would probably make sense to list the two functions in the docs after milliliters/inMilliliters instead of after cubicMeters/inCubicMeters
• I think it might be useful to add a comment to each docs line like 'Alias for milliliters.'

[ianmackenzie]

Oh, and if you could add yourself to the AUTHORS file that would be great 🙂

[g-belmonte]

small doubt: at the module's exposing, should I leave the cubicCentimeters with the other cubic things, or after the milliliters, as in the body of the code?

[g-belmonte]

another doubt: should I add the cubicCentimeter to the list of unitary quantities at the end of the file?

[ianmackenzie]

Oh actually I think the issue is that cubicCentimeters and inCubicCentimeters need to be added to the @docs line after milliliters/inMilliliters; as long as you're using elm-format then they'll automatically be moved to the corresponding place in the module exposing clause. (You do have to make sure they've been added to the exposing clause somewhere first, though.)

Good catch on adding cubicCentimeter! Yes, please do add that (to the code, @docs line and exposing clause - again, if you put it just after milliliter in the @docs line then elm-format should move it to the right place in the exposing clause.)

[g-belmonte]

Adjustments done! :smile:

Checklist:

• [x] Add tests
• [x] Add cubic centimeter methods as milliliter alias
• [x] Add unitary quantity for cubic centimeter
• [x] Add new methods to the docs
• [x] Run elm-format

I hope I didn't miss anything :grin:

[ianmackenzie]

Looks great, thanks!