Added more branches to the code whose coverage is checked.
Add branch details to json report
The json report now includes for each branch which branches have been
executed, missed and what the percentage of covered branches was.
Add exiting branch arc to json report test
Update branch details format
Executed and missing branch arcs are stored in the fields named
'executed_branches' and 'missing_branches' respectively. Both fields
contain a list of two element lists. The first element represents the
source line number and the second one the target line number. Exit
branches have their target line number set to 0.
Fix linting errors