code: function parseVersion(str) {
    var match = /git version ([0-9\.]+)/.exec(str);
  
    if (match) {
      return match[1];
    } else {
      throw new Error('Unable to parse version response', str);
    }
  }
docs: Parses the git version
  @private
  @param {Resolvable|String} str The 'git version' command output
  @throws {Error} parsing error
  @returns {String} the version number