Initial Refactoring of yoshi_otter and Test Implementation

tests/algebra/integral/test_integral_simple.py

@@ -0,0 +1,35 @@
+from yoshi_otter.algebra.integral.simple import Simple
+
+import unittest
+
+
+class MyTestCase(unittest.TestCase):
+
+    def setUp(self):
+        def f(x):
+            return 2*x
+
+        self.f = f
+
+    def test_class_instantiation(self):
+        Simple(self.f)
+
+    def test_riemann(self):
+
+        simple = Simple(self.f)
+
+        integral = simple.riemann(0, 1)
+
+        self.assertAlmostEqual(integral, 1, 5)
+
+    def test_simpson(self):
+
+        simple = Simple(self.f)
+
+        integral = simple.simpson(0, 1)
+
+        self.assertAlmostEqual(integral, 1, 5)  # add assertion here
+
+
+if __name__ == '__main__':
+    unittest.main()