Create new module for Sha2 algorithm
Create a new "common" subproject for hash functions
Isolate common classes and interfaces
Tidy up source code: names, class usage, etc.
Create Sha2 class stub
Use interfaces where possible
Create Sha2 message class stub
Correct test data
Hold initial hash value in a static variable
Create Sha2 message chunk class stub
Fix errors that prevented unit tests from working
Add valid test data for Sha2 Message class
Implement SHA-2 message chunk logic
Add valid test data for SHA2 messages and chunks
Remove fixed paths from gradle config