added planned function signatures, docstrings, and corresponding test case

tests/test_functions.py

@@ -0,0 +1,34 @@
+from unittest import IsolatedAsyncioTestCase
+
+
+class FunctionsTestCase(IsolatedAsyncioTestCase):
+
+    def test_soup_from_url(self):
+        pass
+
+    def test_extract_end_dates(self):
+        pass
+
+    def test_find_relevant_table_rows(self):
+        pass
+
+    def test_convert_number(self):
+        pass
+
+    def test_extract_row_data(self):
+        pass
+
+    def test_extract_all_data(self):
+        pass
+
+    async def test_get_balance_sheet(self):
+        pass
+
+    async def test_get_income_statement(self):
+        pass
+
+    async def test_get_cash_flow_statement(self):
+        pass
+
+    async def test_get_company_financials(self):
+        pass