Fix lint warning
Add Internal namespace to internal components
Create unit test file for API
Create stubs for class datastore and transaction
Create skeleton for transaction class
Create skeleton for datastore API
Move typedefs to datastore.h, fix reference to those typedefs
Create transaction stack and record method
More line breaks to increase readability, change friend class declaration of internal datastore
Fix lint errors
Implement transaction APIs
Move typedefs to a separate header file
Modify implementation of operation queue in transaction class
Add unit test as friend class for InternalDataStore
Add unit test for Transaction class
Add Test Coverage calculation
Add code coverage result to .gigitgnore