_analyze_tables_: pull_requests, milestone

This data as json

table	column	total_rows	num_null	num_blank	num_distinct	most_common	least_common
pull_requests	milestone	608	573	0	15	[["None", 573], [6026070, 6], [3268330, 4], [8711695, 3], [6346396, 3], [5512395, 3], [5471110, 3], [7558727, 2], [5971510, 2], [4471010, 2]]	[[5234079, 1], [5533512, 1], [5897911, 1], [6055094, 1], [9700784, 1], [4471010, 2], [5971510, 2], [7558727, 2], [8355157, 2], [8711695, 3]]