Added option to import all the commits

[revolter]

Added modifications according to this comment.

[IonicaBizau]

Well, I meant to change it locally, on your machine. 😄

Since it will import all commits, the calendar will not show your commits only...

However, we could add the --author option that will import the commits of an author.

[revolter]

I know, but I thought that since I got it working, maybe others would want to use it.

[IonicaBizau]

Hey @revolter!

I'm going to merge this in the new version. Could you please add yourself as contributor in package.json? 😄

Thanks!