Initial support of Drone

[vhatsura]

The pull request add initial support of Drone. to fix #1658

[vhatsura]

Hey, @arturcic!
Could you look into PR, please? It's important for us due to we cannot use git version with Drone in case of build source code from pull request (git version can resolve current branch to calculate version).

[vhatsura]

@JakeGinnivan , @SimonCropp , can you look into this PR, please?

[SimonCropp]

@vhatsura sorry, i am no longer contributing to this project

[arturcic]

I guess adding Drone is a good addition, as it allows building on ARM chip. I guess we could also add support for building GitVersion on ARM as Libgit2Sharp is already adding supporting for ARM.

[arturcic]

@vhatsura thank you for you contribution! Do you mind checking how it works on Drone CI with the latest changes and give us feedback? And sorry it took so long.

[vhatsura]

@arturcic, sure. will check it. To be honest, GitVersion worked on Drone CI, however, during building PRs was some issues with branch identification.

[arturcic]

Now that the changes are merged hope it works as expected.