The main purpose is to evaluate the clinical response, safety and survival of the FDA approved drugs Dabrafenib, Trametinib in combination with Metformin. Investigators hypothesize that the combination of an FDA approved non toxic dose of oral Metformin with the B-Raf inhibitor, Dabrafenib and the MEK inhibitor, Trametinib will yield little toxicity and improve clinical outcomes in terms of objective response rates and survival in metastatic melanoma patients.