Make carbonifer available as Go library

[Joffref]

Closes: #40

Thanks to this PR GetEstimationFromInstanceType(), GetEstimation() and GetResource() will be available as part of carbonifer Go Lib.

Note to the maintainers: I had struggle with the way viper is used to import data, I make an ugly workaround. I'm open to your suggestion on this point in order to find the best way to patch this. 😄

[obierlaire]

Thanks a lot @Joffref for this first contribution ❤️ That's much appreciated !
I haven't had time to properly review it yet, that's a nice work!
However, I've noticed a few things:

• CI is failing: golangci-cli found one tiny error
• Even if it's pretty straightforward GetEstimation() should have a test. It's not a big deal if you don't have time though.

The viper part does not look that ugly, I'll have a look later to see if we can find a nicer way

Again, thanks!

[Joffref]

Hey @obierlaire, I've made few changes on the PR, based on your comments. Hope it will be good this time, let me know if there is something to modify in it.

[obierlaire]

I think you need to rebase once #47 will be merged

[Joffref]

I think you need to rebase once #47 will be merged

I agree 👍 Waiting to the update on your side

[obierlaire]

#47 merged, you can rebase your branch

[obierlaire]

@Joffref I pushed ad7d82f to your PR in order to have one single rationalized way to init Viper and set data.path variable, always from the go project root directory, and not relative to the caller. That's more DRY and seems to work...

[Joffref]

Nice one ! It will be better like this 👍