lib/sysrev/sysrev.js
function(user, systemId, message, cb) {
    logger.info('committing revision: ' + systemId + ', ' + message);
    var repoPath = _meta.repoPath(systemId);
    git.commit(repoPath, message, user.name, user.email, cb);
  }
function(user, systemId, message, cb) {
    logger.info('committing revision: ' + systemId + ', ' + message);
    var repoPath = _meta.repoPath(systemId);
    git.commit(repoPath, message, user.name, user.email, cb);
  }
make a commit to local git repository
TODO: implement seperate push functionality
TODO: replace with git hub id