Stub out db upsert code for stations table in test_db.py.

See table definition at 
W1CDN/aprs_tool#30 (comment).

test_db.py

@@ -0,0 +1,29 @@
+
+# Learn how to update database
+
+import sqlite3
+
+def get_db_connection():
+    conn = sqlite3.connect('database.db')
+    conn.row_factory = sqlite3.Row
+    return conn
+
+conn = get_db_connection()
+
+# example https://stackoverflow.com/a/50718957/2152245
+query1 = "INSERT INTO players (user_name, age) \
+VALUES('steven', 32) \
+ON CONFLICT(user_name) \
+DO UPDATE SET age=excluded.age;"
+
+query2 = "INSERT INTO stations (id, 'from', frames_id, last_heard_unix, count) \
+VALUES(1, 'KC9TZN-9', 4068, 1687623864, 1) \
+ON CONFLICT(id) \
+DO UPDATE SET count = count + 1;"
+
+query3 = "INSERT INTO stations ('from', frames_id, last_heard_unix, count) \
+VALUES('KC9TZN-9', 4068, 1687623864, 1)"
+
+conn.execute(query2)
+conn.commit()
+conn.close()