Patch for git abbreviation length

Newer versions of git will report the abbreviation of the revision hash with a dynamic number of letters. This may cause problems for teams mixing different git versions. Patch specifies an abbreviation length of 7 (the git default).

Git describe passthrough arguments

semver-git now accepts pass-through arguments for "git describe" so that tags may be filtered.

Remove deprecated construct

Task.leftShift(Closure) method has been deprecated in Gradle 3.0 and …

…is scheduled to be removed in Gradle 5.0

Use project dir in getGitVersion

Merge pull request #2 from zombiedev/project-dir

use project dir in getGitVersion