Regenerate client with fixed swagger

[aethanol]

This PR regenerates the client with an adapted generator based off of #15.
The current client is not up to date, and has old bugs that were fixed in the past year or so.
This PR also moves to go module using name module github.com/grafeas/client-go, and moves away from keeping the version in the generated directory.
Now we generate into two paths, grafeas and projects for the two different swagger files. Updating documentation included in README.md

[aethanol]

Hey @wkozlik , just tagging you here for visibility.

[aethanol]

Edit: raised a fix, and manually edited what will be included in the fix here.
swagger-api/swagger-codegen#12076

Turns out this is being affected by a bug in swagger-codegen, looking into a fix.

[wkozlik]

Thank you for this contribution. This looks great!

[aethanol]

Thanks for reviewing @wkozlik ! Would you be able to tag a version when you get a chance as well? I have it as 1.0.0 in the config.go.json file.
Otherwise this should be good to go. I'll plan on updating this PR whenever the swagger-codegen change gets merged.

[wkozlik]

Thank you for this fix. It is looking great. I need to update the build step, to be able to merge this PR.

[aethanol]

@wkozlik anything I can help contribute to?

[wkozlik]

I am sorry for the delay. We should be okay now. Could you resolve merge conflicts?

[aethanol]

No worries! just resolved, should be good to go