put code into functions and 'main' in flicker.py.

This is just so I can start to 'turn things on and off' (via
comments).

src/flicker.py

@@ -1,9 +1,9 @@
 import csv
 import datetime
 
+def tally_readings_per_second():
     time_tallies = dict()
     tally_totals = dict()
-
     with open("data/test-data.csv") as csv_file:
         csv_reader = csv.reader(csv_file, delimiter=",")
         for r in csv_reader:
@@ -18,10 +18,19 @@ with open("data/test-data.csv") as csv_file:
                 tally_totals[r2] = (tally_totals[r2]) + 1
             else:
                 tally_totals[r2] = 1
-    print(tally_totals.items())
-with open("data/results/reading-per-sec.csv", mode="w") as result:
+                # print(tally_totals.items())
+    return tally_totals
+
+def save_tally_totals(tally_totals):
+    with open("data/results/readings-per-sec.csv", mode="w") as result:
         wtr = csv.writer(result)
         for k, v in tally_totals.items():
             print(f"{k}: {v}")
             wtr.writerow([k,v])
 
+def main():
+    time_tallies = tally_readings_per_second()
+    save_tally_totals(time_tallies)
+    
+if __name__ == "__main__":
+    main()