Implement predict_proba with test.

Fix tree overload with dataset in nodes only needed in tests

README.md

@@ -1,2 +1,14 @@
 # STree
 Oblique Tree classifier based on SVM nodes
+
+## Example
+
+```python
+python main.py
+```
+
+## Tests
+
+```python
+python -m unittest tests.Stree_test tests.Snode_test
+```