Update LIVR test suite to v0.6
Add "url", "iso_date" rules, support for simpler syntax (without double braces) for "one_of" and "list_of"
Implement "remove" and "leave_only" rules, add flags support to "like" rule
Correct error code in LIVR suite for "not_empty_list" negative test with empty object ({})
Change arguments order in assertEquals() calls for correct GOT\EXPECTED test output hints
Change function names to camelCase