Rework parsers to use subparsers

Signed-off-by: Thanh Ha <thanh.ha@alumni.carleton.ca>
Move APIs to an API file

Signed-off-by: Thanh Ha <thanh.ha@alumni.carleton.ca>
Add a YAML config file format and unit tests

Signed-off-by: Thanh Ha <thanh.ha@alumni.carleton.ca>
Rename project to Sym

Signed-off-by: Thanh Ha <thanh.ha@alumni.carleton.ca>