Expand Tests (#6)

Expand tests into two files.

Author: forsyth2

.travis.yml

@@ -1,3 +1,5 @@
 language: python
 
-script: python calculator/calculator_test.py
+script:
+  python calculator/test_calculator_simple.py;
+  python calculator/test_calculator_advanced.py

calculator/test_calculator_advanced.py

@@ -0,0 +1,15 @@
+import calculator as c
+import unittest
+
+class CalculatorTest(unittest.TestCase):
+    def test_sum1(self):
+        n = 10
+        value1 = 0
+        for i in range(1, n + 1):
+            value1 = c.add(value1, i)
+        self.assertEqual(value1, 55)
+        value2 = c.divide(c.multiply(n, c.add(n, 1)), 2)
+        self.assertEquals(value2, 55)
+
+if __name__ == "__main__":
+    unittest.main()