Support for workingDirectory for version goal

[stefandesmit-tomtom]

When executing "mvn -f someDir/pom.xml ci-friendly-flatten:version", we get:
"Failed to retrieve version tag, continuing with default tag:"

This is probably caused by VersionProviderImpl simply calling:
Runtime.getRuntime().exec(command); where command is "git ..."
while not in the actual repository directory.

There's also a configuration property but this does not fix it.
Proposed (but not tested) solution:
Runtime.getRuntime().exec(command, null, workingDirectory)

[ayoukhananov]

@stefandesmit-tomtom If there is no tag we put a default tag {project.artifactId}-0.0.0.1 .
Which also can be overrides by passing this param -Ddefault.tag=????

Did you try it ?

[stefandesmit-tomtom]

There is a tag (and default tag). It does find the default tag from pom, but not the tag from git.
I see now that something was not formatted well in my comment (put

instead of someDir, which didn't show up outside of editing mode) which was hiding the important information that we execute the command outside of the git directory.
(just putting this in some shell & first cd into the directory makes everything work ok)
"mvn -f someDir/pom.xml ci-friendly-flatten:scmTag" does work, because that's using the whole Scm abstraction. it's just the version goal that doesn't.