Bug when no gene set has factor > 0.01

[marcdubybroad]

Gui_utils.py line 228
map_temp = {'cluster': name, 'factor': name, 'label': row['gene_set']}
TypeError: string indices must be integers

[marcdubybroad]

Issue is list_factor = ['', '', '', ''], so list_factor['gene_set'] causes an issue
Could limit adding those elements to the list_factor list, but then list_factor and exp_lambda would have different dimensions