Update CHANGELOG.md

update version: 3.1.2

update test case

Merge branch 'feature/delay_check'

change holo_proxy to readonly

1, check the cell class type and so on after the list appears; 2, provide default cell class for row and default header and footer class for section.

Update CHANGELOG.md

update version: 3.1.1

Merge branch 'unit_test_case'

Merge branch 'feature/fix_api'

unit test case

unit test case

unit test case for: `holo_updateRowsInSection:`, `holo_remakeRowsInSection:` and `holo_insertRowsAtIndex:inSection:`

Merge branch 'feature/fix_api' into unit_test_case

code comment