Can Chipotle keep climbing?The post-Brian Niccol era is underway at Chipotle Mexican Grill (CMG 5.06%), and it's off to an inauspicious start.Shares of the burrito chain are down about 8% since the company missed top-line estimates and reported its slowest earnings growth in more than two years.Chipotle posted same-store sales growth of 6%, which contributed to revenue's 13% rise to $2.79 billion, though that fell short of the analyst consensus at $2.82 billion. Further down the income statement, its restau ...