added test framework (#113)

* added test framework

* added toString on motors

* enabling logs

libs/tests/README.md

@@ -0,0 +1,35 @@
+# tests
+
+A unit test framework
+
+## Defining tests
+
+Tests are registered as event handlers. They will automatically run once ``on start`` is finished.
+
+```blocks
+tests.test("lgB set speed 10", () => {
+    motors.largeB.setSpeed(10);
+    loops.pause(100)
+    tests.assertClose("speedB", 10, motors.largeB.speed(), 2)
+});
+```
+
+## Assertions
+
+The library has various asserts that will register fault. Note that since exceptions are not available, assertion failure **do not** stop the program execution.
+
+* **assert** checks a boolean condition
+
+```blocks
+tests.assert("speed positive", motors.largeB.speed() > 0)
+```
+
+* **assert close** checks that a numberical value is within a particular range
+
+```blocks
+tests.assertClose("speed", motors.largeB.speed(), 10, 2)
+```
+
+```package
+tests
+```