Provide Test Suite for C and Python

[deepbrook]

Implement tests for C and Python code base.

C Tests

• TestCreateDummyTree
• TestOrderPushing
• TestOrderPopping
• TestRemoveOrder
• TestCreateRoot
• TestAddNewLimit
• TestLimitExists
• TestLimitIsRoot
• TestHasGrandpa
• TestGetGrandpa
• TestGetMaximumLimit
• TestGetMinimumLimit
• TestGetHeight
• TestGetBalanceFactor
• TestReplaceLimitInParent
• TestRemoveLimit
• TestRotateLL
• TestRotateLR
• TestRotateRR
• TestRotateRL

Python Tests

Cython-bound C function tests:

• TestOrderPushing
• TestOrderPopping
• TestRemoveOrder
• TestAddNewLimit
• TestRemoveLimit

Python Functions and Methods:

• TestCreateBook
• TestUpdateBook
• TestDeleteOrder
• TestAddOrder
• TestAddLimit
• TestRemoveLimit