fall-summer 7wk baseline comparison fxn

functions.py
- anydiag_baseline_comparison function, returns
dict of total number of any diagnosis visits during
first 7 weeks of flu season and last 7 summer weeks
before start of flu season
histogram # cases for fall/summer BL anydiag

Supp_fall_summer_baselinbars.py
- draw bar histogram comparing number of
any diagnosis visits during fall and summer
7 week baseline

fall_summer_baselinebars.sql
- extract any diagnosis data from fall and
summer 7 week baseline from SDI database