use project dir in getGitVersion

[ghost]

Rather than running git describe in the current working dir, run it in
the directory of the gradle project. This allows projects that come from
git submodules to use the versions from their repo's tags.

[ghost]

I have not yet signed the Cinnober CLA, but I'll send it to you soon.

[mbrannstrom]

Zombiedev, have you signed the CLA and heard anything from Cinnober yet?

I'm not working at Cinnober anymore but I think this should be merged and released as a bug-fix, i.e. as version 2.2.2.

[ghost]

@mbrannstrom, I just emailed it to them.

I don't know how active this project is or when they'll merge this PR, but you can always do something like this in the meantime:

buildscript {
    repositories {
        mavenCentral()
        jcenter()
        maven { url "https://jitpack.io" }
    }

    dependencies {
        classpath "com.github.zombiedev:semver-git:98f7bb63b0"
    }
}

[MikaelUmaN]

Thank you for your contribution. I will try to find out who are on the mailing list aforementioned and why no response was sent to you.