Added test cases.

test.py

@@ -0,0 +1,18 @@
+import ods2md
+
+import unittest
+import os.path
+import io
+
+class Test(unittest.TestCase):
+    def perform_test(self, base):
+        output = io.StringIO()
+        ods2md.main(os.path.join('test', base + '.ods'), output)
+        with open(os.path.join('test', base + '.md'), 'r') as f:
+            self.assertMultiLineEqual(f.read(), output.getvalue())
+
+    def test_sample(self):
+        self.perform_test('sample')
+
+    def test_padded(self):
+        self.perform_test('padded')